Today we will get acquainted with a profession, the existence of which many of us have never thought about. We are all used to buying at the pharmacy in full confidence that they will help and not harm. But who is responsible for the safety of pharmaceuticals?

Health care managers, pharmacologists, scientists, medical equipment suppliers, nurses and paramedics, insurance experts and psychologists: tens of thousands of professionals are responsible for the smooth operation of the healthcare industry! To delve into the intricacies of the work of each and see the interesting features of medical specialties is possible only from the inside, being in a place where patients are usually not allowed to look.

Before being marketed, every drug goes through a long journey, from animal testing in the lab to testing on real patients in hospitals. And along the way, each drug accompanies clinical research specialist.

Our expert: Lev Korolkov, St. Petersburg, clinical research specialist at OCT.

About a profession with a strange name

My position in Russia sounds like a clinical research specialist, but it's official, in short - a monitor. Foreign name - clinical research associate or simply CRA.

In general, after graduating from the St. Petersburg State Chemical Pharmaceutical Academy, I had little idea of ​​what area of ​​pharmaceuticals I would work in. Once my classmate, who already worked as a monitor, told how she travels to different cities and conducts some kind of research there. After learning more about the essence of the work, I decided that this is a good option. Since then, clinical research has been my profession.

About drug testing

In fact, people have been thinking about the safety of medicines relatively recently. Serious development of clinical trials of new drugs began after the largest pharmacological tragedies of the 20th century: sulfanilamide and thalidomide.

The first happened in 1937, when the pharmaceutical company M. E. Massengill released a liquid form of a sulfa drug for children - before the invention of antibiotics, this group of drugs was the most effective in the fight against infectious diseases. However, the solvent used for the new mixture turned out to be terribly poisonous. Shortly after the launch of the drug, it became known that 8 children and 1 adult patient died after taking it. Pharmacists sounded the alarm and began a campaign to recall the drug from pharmacies, but before the end of the proceedings, the deadly mixture managed to claim the lives of 107 people.

The thalidomide tragedy happened 20 years later, when the uncontrolled use of thalidomide, a drug recommended for pregnant women as a sedative, led to the birth of more than 10 thousand children with severe malformations.

By the way, quite recently, the Americans honored the last journey of the legendary employee of the US Food and Drug Administration named Francis Oldham Kelsey, whose courage prevented a tragedy on the other side of the Atlantic (even before the first cases of congenital deformities, the woman suspected something was wrong with thalidomide and refused to register it for sale in the United States).

Since then, it has become clear that every new drug needs to be tested for safety and efficacy, as well as to ensure that its trials are ethical and do not harm the volunteers and patients who agreed to try the new drug on themselves.

On romance and travel

Travel really does take up a significant part of a clinical research specialist's job. The fact is that to obtain objective statistical data, it is almost impossible to find the right number of suitable patients in one city. Therefore, many hospitals are needed - in different cities, and representatives of my specialty travel a lot, and by air: otherwise we would lose too much time on the road.

In addition, in one hospital, patients will be treated by the same research doctors, one laboratory, one CT machine will be used. An error in dosing, measuring a tumor or measuring potassium in the blood (I'm not talking about data forgery) will lead to a systematic inaccuracy of all data. This will put an end to the entire clinical trial. But if this happens in only one hospital out of many participating in the study, then the data may still be reliable.

At first, trips to different cities seemed like real romance to me. But over time, having flown hundreds of thousands of kilometers, I got used to it, and this became the usual mode. Like the hero of George Clooney in the movie “Up in the Sky”, I literally became a professional air passenger: I immediately find the fastest line at the pre-flight inspection, I pack my suitcase in 10 minutes, in which everything has its place, and I know the airport layouts as my own. five fingers.

As a rule, each of my business trips lasts 1-2 days. The night before, I fly from St. Petersburg to another city - Krasnoyarsk, Kazan, Barnaul, Rostov-on-Don ... In the morning I wake up in a hotel and go to a medical facility where our drug is being tested. There I communicate with doctors and check all the documents indicating that patients agree to take part in drug testing. After lunch, I check the hospital's drug supplies, laboratory samples, and all materials needed for the study. In the evening I go to the airport again, and from there - back to St. Petersburg.

I work regularly on the road, this is already the norm: sit in the waiting room / taxi / plane and write another report or letters to the project manager. I can’t say that this is a comfortable lifestyle, because night flights (“zombie flights”, as I call them) or flights after a working day do not allow you to relax or just sleep well, but even you get used to it. If I have free time after work and I'm in another city, I try to take a walk in unfamiliar places or go to the gym in the hotel.

Often my friends think that such a schedule is crazy. Here, perhaps, not everything is so clear. I would not say that this work is critically different from many others in terms of workload. It all depends on the current situation and the availability of projects. When the project is in full swing and the deadlines are running out, then, of course, you have to work on the plane, and in a taxi, and at home on the weekends, but this is rather a temporary phenomenon. At least in our company. In investment banking, for example, they work much more, as far as I know. Personally, I quite manage to combine personal life with work. Of my 15 fellow monitors, seven are married. We have a friendly team: when the schedule allows, we regularly get together in pubs.

For representatives of my profession, the balance of following instructions and psychological skills is important. The first is taught in trainings, and without it in any way. And you learn psychology mostly on your own: you look for an approach to different researchers, smooth out conflicts, set up doctors for active work.

About patients who are ready for anything

I will say a few words about the document called "Informed Consent". It should not be thought that the verification of the fact that the patient knowingly agreed to take part in the trial of the drug is an empty formality. The signing of the consent and the correct reflection of this process in the patient's chart is the cornerstone of the monitor's visit, the verification of which makes it possible to understand a lot about the observance of the patient's rights.

How is it that a person voluntarily agrees to try a new medicine on himself? First, patients never pay anything to participate in a clinical trial. But volunteers can be paid, especially when the safety of the drug is being tested (as a rule, healthy people are involved for this).

In addition to free treatment, participants also receive a thorough free examination. By the way, it is not uncommon for patients to be treated outside of the study with similar, but approved drugs. But not all of these drugs can afford them.

In other cases, patients agree to the trial because they have already tried all the existing treatments and nothing has worked for them. They simply have no other choice but to try new drugs that are still under investigation. This is especially true for cancer patients.

About placebo and nocebo

A placebo drug (lat. placere - “I will like you”) does not work due to a real effect, but simply because it is positively perceived by the patient, psychologically affects him. There is also the opposite phenomenon - nocebo ("I will harm") - when, due to the subjective perception of the drug, a deterioration occurs.

There is also such an interesting term as randomization - the process of assigning research subjects to treatment or control groups in a random way, which minimizes subjectivity. The process is needed so that it is not the doctor who decides who will be treated with what (there is a possibility that "mild" patients will be given a placebo, and "severe" - the study drug), but the case.

The blind method of the study is that the patient does not know which drug he will take: study / placebo / comparator drug. The double-blind method is the same, but when the experimenter (and the monitor, and often the statistician) does not know what the patient is taking. Both are necessary to reduce subjective factors (the "placebo effect") that may affect the results of the study.

Everything is clear with the patient: if he knows that he is taking the investigational drug, then he has high expectations from the treatment. This may affect the subjective assessment. But the doctor also gives a subjective assessment of the current state of the patient, which, in turn, can also be influenced by information about the drug.

There are also so-called vulnerable subjects of research. These include medical students, clinic staff, military personnel and prisoners, as well as terminally ill people, the homeless, refugees, minors, and in addition persons unable to give consent. If these categories participate in the study, we always control that they are not pressured by management.

Situations when the drug (real or placebo) does not work, and the patient has severe adverse events, are always prescribed in the protocol of a clinical trial. If a person's condition worsens or he simply decides to abandon the experiment, he will not be forced to be treated forcibly. In this case, the patient, if necessary, is provided with medical assistance or referred to other specialists.

About self-realization

It may seem to someone that the work of a clinical research specialist is a rather boring clerical task that does not require any special knowledge and skills. But this is not so: I always feel responsible, because my punctuality and attentiveness determine how fully the possible side effects associated with taking the drug will be reflected, and, no less important, whether the rights of patients will be respected. After all, every day thousands of people voluntarily agree to test a medicine on themselves, which, perhaps in a few years, will allow faster and more reliable treatment of a particular disease.

Are new drugs really that effective? I do not presume to judge - I am just a small part of a large system that accompanies medicine from a test tube to a pharmacy counter. But personally, the effect of treatment with modern drugs is always positive for me. I attribute this to the fact that I do not buy drugs at random, but only after consulting a doctor and proper diagnosis.

Olga Kashubina

Photo thinkstockphotos.com

When using drugs, the effectiveness should exceed the potential risk of side effects (adverse reactions). The "clinical impression" of a drug's efficacy can be misleading, partly due to the subjectivity of the physician and the patient, as well as the bias of the evaluation criteria.

Clinical trials of drugs serve as the basis for evidence-based pharmacotherapy. Clinical study - any study of a drug conducted to obtain evidence of its safety and efficacy with the participation of people as subjects, aimed at identifying or confirming a pharmacological effect, adverse reactions, studying pharmacokinetics. However, before the start of clinical trials, a potential drug goes through a difficult stage of preclinical studies.

Preclinical studies

Regardless of the source of receipt, the study of a biologically active substance (BAS) is to determine its pharmacodynamics, pharmacokinetics, toxicity and safety.

To determine the activity and selectivity of the action of the substance, various screening tests are used, carried out in comparison with the reference drug. The choice and number of tests depend on the objectives of the study. So, to study potential antihypertensive drugs that act presumably as antagonists of a-adrenergic receptors of blood vessels, they study in vitro binding to these receptors. Next, the antihypertensive activity of the compound is studied in animal models of experimental arterial hypertension, as well as possible side effects. As a result of these studies, it may be necessary to chemically modify the molecules of the substance to achieve more desirable pharmacokinetic or pharmacodynamic properties.

Next, a toxicological study of the most active compounds is carried out (determination of acute, subchronic and chronic toxicity), their carcinogenic properties. The determination of reproductive toxicity is carried out in three phases: the study of the overall effect on fertility and reproductive properties of the organism; possible mutagenic, teratogenic properties of drugs and embryotoxicity, as well as effects on implantation and embryogenesis; long-term studies on peri- and postnatal development. The possibilities for determining the toxic properties of drugs are limited and expensive. It should be borne in mind that the information obtained cannot be fully extrapolated to humans, and rare side effects are usually detected only at the stage of clinical trials. Currently, cell cultures (microsomes, hepatocytes, or tissue samples) are sometimes used as an alternative to experimental preclinical evaluation of the safety and toxicity of drugs in animals.

The final task of preclinical studies is the choice of a method for the production of an investigational drug (eg, chemical synthesis, genetic engineering). An obligatory component of preclinical drug development is the development of a dosage form and assessment of its stability, as well as analytical control methods.

Clinical researches

To the greatest extent, the influence of clinical pharmacology on the process of creating new drugs is manifested in clinical trials. Many results of pharmacological studies in animals used to be automatically transferred to humans. Then, when the need for human studies was recognized by everyone, clinical trials were usually carried out on patients without their consent. Known cases of deliberately dangerous research on socially unprotected persons (prisoners, mentally ill, etc.). It took a long time for the comparative design of the study (the presence of an "experimental" group and a comparison group) to become generally accepted. It is likely that it was mistakes in research planning and analysis of their results, and sometimes falsification of the latter, that caused a number of humanitarian disasters associated with the release of toxic drugs, for example, a solution of sulfanilamide in ethylene glycol (1937), as well as thalidomide (1961), which was prescribed as an antiemetic in early pregnancy. At this time, doctors did not know about the ability of thalidomide to inhibit angiogenesis, which led to the birth of more than 10,000 children with phocomelia (a congenital anomaly of the lower extremities). In 1962, thalidomide was banned for medical use. In 1998, thalidomide was approved by the US FDA (Food and Drug Administration) for use in the treatment of leprosy, and is currently undergoing clinical trials for the treatment of refractory multiple myeloma and glioma. The first government agency to regulate clinical trials was the US FDA, which proposed in 1977. the concept of good clinical practice (Good Clinical Practice, GCP). The most important document defining the rights and obligations of participants in clinical trials was the Helsinki Declaration of the World Medical Association (1968). After numerous revisions, the final document appeared - the Guidelines for Good Clinical Practice (ICH Guidelines for Good Clinical Practice, ICH GCP). The provisions of the ICH GCP are consistent with the requirements for conducting clinical trials of drugs in the Russian Federation and are reflected in the Federal Law "On Medicines" (No. 86-FZ of 06/22/98, as amended on 01/02/2000). Another official document regulating the conduct of clinical trials in the Russian Federation is the industry standard "Rules for conducting high-quality clinical trials in the Russian Federation".

According to these documents, good clinical practice is understood as “a standard for planning, executing, monitoring, auditing and documenting clinical trials, as well as processing and reporting their results; a standard that serves as a guarantee for society of the reliability and accuracy of the data obtained and the results presented, as well as the protection of the rights, health and anonymity of research subjects.

The implementation of the principles of good clinical practice ensures compliance with the following basic conditions: the participation of qualified investigators, the distribution of responsibilities between study participants, a scientific approach to study design, data recording and analysis of the results presented.

The execution of clinical trials at all its stages is subject to multilateral control by the customer of the study, audit, state control bodies and an independent ethical committee, and all activities as a whole are carried out in accordance with the principles of the Declaration of Helsinki.

When conducting clinical trials in humans, the researcher solves three main tasks:

1. Determine how pharmacological effects identified in animal experiments correspond to data that can be obtained when using drugs in humans;

2. Show that the use of drugs has a significant therapeutic effect;

3. Prove that the new drug is safe enough to be used in humans.

Ethical and legal standards of clinical research. Ensuring patient rights and ethical compliance is a complex issue in clinical trials. They are regulated by the above documents, the Ethics Committee serves as a guarantor of the observance of the rights of patients, the approval of which must be obtained before the start of clinical trials. The main task of the Committee is to protect the rights and health of the subjects, as well as guarantee their safety. The ethics committee reviews information about the drug, evaluates the structure of the clinical trial protocol, the content of the informed consent and biographies of the investigators, followed by an assessment of the potential risk to patients and compliance with their guarantees and rights.

The patient may participate in clinical trials only with full and informed voluntary consent. Each patient must be fully informed of the possible consequences of their participation in a particular clinical trial. He signs an informed written consent, which sets out the objectives of the study, its benefits for the patient if he participates in the study, unwanted adverse reactions associated with the study drug, providing the subject with the necessary medical care if they are detected during the trial, information about insurance. An important aspect of protecting the rights of the patient is the observance of confidentiality.

Participants in a clinical study. The first link in clinical trials is the drug developer or sponsor (usually a pharmaceutical company), the second is the medical institution on the basis of which the test is carried out, and the third is the patient. Contract research organizations can act as a link between the customer and the medical institution, assuming the tasks and responsibilities of the sponsor and exercising control over this study.

Conducting clinical trials. The reliability of clinical trial results depends entirely on how carefully they are planned, conducted, and analyzed. Any clinical trial should be carried out according to a strictly defined plan (research protocol), which is identical for all medical centers participating in it.

The study protocol includes a description of the purpose and design of the study, criteria for inclusion (and exclusion) in the trial and evaluation of the effectiveness and safety of the treatment, treatment methods for study subjects, as well as methods and timing for assessing, recording and statistical processing of efficacy and safety indicators.

The objectives of the test must be clearly stated. When testing a medicinal product, this is usually the answer to the question: “How effective is this therapeutic approach under certain conditions in comparison with other therapeutic methods or no therapy at all?”, As well as an assessment of the benefit / risk ratio (at least in terms of reporting the frequency of adverse reactions) . In some cases, the goal is narrower, such as determining the optimal dosing regimen for the drug. Regardless of the goal, it is necessary to clearly articulate what end result will be quantified.

The ICH GCP rules do not allow the use of material incentives to attract patients to participate in the study (with the exception of healthy volunteers involved in the study of pharmacokinetics or bioequivalence of drugs). The patient must meet the exclusion criteria.

Usually, pregnant, breastfeeding, patients with severe liver and kidney dysfunction, aggravated by an allergic history are not allowed to participate in studies. It is unacceptable to include in the study incapable patients without the consent of the trustees, as well as military personnel, prisoners.

Clinical trials in juvenile patients are performed only when the investigational drug is intended exclusively for the treatment of childhood diseases or the study is conducted to obtain information about the optimal dosage of the drug for children. Preliminary studies of this drug in adults or adults with a similar disease are needed, the results of which serve as the basis for planning studies in children. When studying the pharmacokinetic parameters of drugs, it should be remembered that as the child grows, the functional parameters of the child's body change rapidly.

The study should include patients with a clearly verified diagnosis and exclude patients who do not meet predetermined criteria for diagnosis.

Usually, patients with a certain risk of adverse reactions are excluded from the study, for example, patients with bronchial asthma when testing new (3-blockers, peptic ulcer - new NSAIDs.

The study of the action of drugs in elderly patients is associated with certain problems due to the presence of concomitant diseases in them that require pharmacotherapy. In this case, drug interactions may occur. It should be borne in mind that side effects in elderly patients may occur earlier and at lower doses than in middle-aged patients (for example, only after widespread use of the NSAID benoxaprofen was it found to be toxic to elderly patients at doses relatively safe for younger patients). ).

The study protocol for each group of subjects should provide information about drugs, doses, routes and methods of administration, periods of treatment, drugs, the use of which is allowed (including emergency therapy) or excluded by the protocol.

In the section of the protocol “Evaluation of effectiveness”, it is necessary to list the criteria for evaluating the effectiveness, methods and terms for registering its indicators. For example, when testing a new antihypertensive drug in patients with arterial hypertension, 24-hour blood pressure monitoring, measurement of systolic and diastolic pressure in the patient’s lying and sitting position are used as effectiveness criteria (in addition to the dynamics of clinical symptoms), while mean diastolic pressure in the patient’s position is considered effective. seated less than 90 mmHg Art. or a decrease in this indicator by 10 mm Hg. Art. and more after the end of treatment compared with the original figures.

The safety of drugs is assessed throughout the study by analyzing physical data, anamnesis, performing functional tests, ECG, laboratory tests, measuring pharmacokinetic parameters, recording concomitant therapy, and side effects. Information about all adverse reactions noted during the study should be entered in the individual registration card and the adverse event card. Adverse event - any undesirable change in the patient's condition, different from the state before the start of treatment, related or not related to the study drug or any other drug used in concomitant drug therapy.

Statistical processing of clinical trial data is necessary, since usually not all objects of the population of interest are studied, but a random selection of options is carried out. The methods intended for solving this statistical problem are called randomization methods, that is, the distribution of subjects into experimental and control groups randomly. The randomization process, duration of treatment, sequences of treatment periods, and trial termination criteria are reflected in the study design. Closely related to the problem of randomization is the problem of study blindness. The purpose of the blind method is to eliminate the possibility of the influence (conscious or accidental) of a doctor, researcher, patient on the results obtained. The ideal is a double-blind test where neither the patient nor the doctor knows what treatment the patient is receiving. To exclude a subjective factor influencing treatment, a placebo (“dummy”) is used during clinical trials, which makes it possible to distinguish between the actual pharmacodynamic and suggestive effects of the drug, to distinguish the effect of drugs from spontaneous remissions during the course of the disease and the influence of external factors, to avoid obtaining false negative conclusions ( for example, equal efficacy of the study drug and placebo may be due to the use of an insufficiently sensitive method of evaluating the effect or a low dose of the drug).

The individual registration card serves as an information link between the investigator and the trial sponsor and includes the following mandatory sections: screening, inclusion/exclusion criteria, visiting blocks, prescribing the investigational drug, prior and concomitant therapy, registration of adverse drug reactions and completion of the clinical trial.

Phases of clinical research. Clinical trials of drugs are carried out in healthcare institutions licensed to conduct them. Persons participating in clinical trials should receive special training in the conduct of high-quality clinical trials. Control over the testing is carried out by the Department of State Control of Medicines and Medical Equipment.

The sequence of studying drugs is divided into four phases (Table 9-1).

Table 9-1. Phases of clinical trials

Phase I is the initial stage of clinical trials, exploratory and especially carefully controlled. Usually 20-50 healthy volunteers take part in this phase. The purpose of phase I is to determine the tolerability of the drug, its safety in short-term use, the expected efficacy, pharmacological effects and pharmacokinetics, as well as obtaining information on the maximum safe dose. The test compound is administered in low doses with a gradual increase until signs of toxic effects appear. The initial toxic dose is determined in preclinical studies; in humans, it is 100 experimental. Mandatory monitoring of the concentration of the drug in the blood is carried out with the determination of a safe range, unknown metabolites are detected. Side effects are recorded, the functional state of organs, biochemical and hematological parameters are examined. Prior to the start of the test, a thorough clinical and laboratory examination of volunteers is carried out to exclude acute and chronic diseases. If it is impossible to test the drug on healthy people (for example, cytotoxic drugs, 1C against AIDS), studies are carried out on patients.

Phase II is the key one, since the data obtained determine the feasibility of continuing the study of a new drug in a larger number of patients. Its purpose is to prove the clinical efficacy of J1C when tested on a specific group of patients, to establish the optimal dosing regimen, to further study the safety of the drug in a large number of patients, and to study drug interactions. Compare the efficacy and safety of the study drug with the reference and placebo. This phase usually lasts about 2 years.

Phase III - full-scale, expanded multicenter clinical trials of the drug in comparison with placebo or reference drugs. Usually, several controlled studies are carried out in different countries according to a single protocol for clinical trials. The information obtained clarifies the effectiveness of the drug in patients, taking into account concomitant diseases, age, gender, drug interactions, as well as indications for use and dosing regimen. If necessary, pharmacokinetic parameters are studied in various pathological conditions (if they have not been studied in phase II). After the completion of this phase, the pharmacological agent acquires the status of a drug after registration (a process of successive expert and administrative-legal actions) with entry into the State Register and assignment of a registration number to it. The documents required for the registration of a new drug are reviewed by the Department of State Control of Medicines and Medical Equipment and sent for examination to the specialized commissions of the Pharmacological and Pharmacopeial Committees. The commissions may recommend that the manufacturer conduct additional clinical studies, including bioequivalence (for generic drugs). With a positive expert assessment of the submitted documents, the commissions recommend that the Department register the drug, after which the drug enters the pharmaceutical market.

Phase IV and post-marketing research. The purpose of phase IV is to clarify the features of the action of drugs, an additional assessment of its effectiveness and safety in a large number of patients. Extended post-registration clinical trials are characterized by the widespread use of a new drug in medical practice. Their purpose is to identify previously unknown, especially rare side effects. The data obtained can serve as the basis for making appropriate changes to the instructions for use of the drug.

evidence-based medicine

The concept of evidence-based medicine, or evidence-based medicine, proposed in the early 1990s, implies the conscientious, accurate and meaningful use of the best results of clinical trials to select the treatment of a particular patient. This approach reduces the number of medical errors, facilitates the decision-making process for practitioners, hospital administrations and lawyers, and reduces healthcare costs. The concept of evidence-based medicine offers methods for correctly extrapolating data from randomized clinical trials to address practical issues related to the treatment of a particular patient. At the same time, evidence-based medicine is a concept or method of decision-making; it does not claim that its conclusions fully determine the choice of drugs and other aspects of medical work.

Evidence-based medicine is designed to address the following important questions:

Can you trust the results of a clinical trial?

What are these results, how important are they?

Can these results be used to make decisions in the treatment of specific patients?

Levels (classes) of evidence. A convenient mechanism that allows a specialist to evaluate the quality of any clinical trial and the reliability of the data obtained is the rating system for evaluating clinical trials proposed in the early 1990s. Usually, there are from 3 to 7 levels of evidence, while as the serial number of the level increases, the quality of the clinical trial decreases, and the results seem less reliable or have only indicative value. Recommendations from studies at various levels are usually denoted in Latin letters A, B, C, D.

Level I (A) - well-designed, large, randomized, double-blind, placebo-controlled studies. It is customary to refer to the same level of evidence data obtained as a result of a meta-analysis of several randomized controlled trials.

Level II (B) - small randomized and controlled trials (if statistically correct results are not obtained due to the small number of patients included in the study).

Level III (C) - case-control or cohort studies (sometimes referred to as level II).

Level IV (D) - information contained in the reports of expert groups or consensus of specialists (sometimes referred to as level III).

"Endpoints" in clinical trials. Primary, secondary, and tertiary “endpoints” can be used to evaluate the effectiveness of the new J1C in clinical trials. These primary outcomes are assessed in controlled comparative studies of treatment outcomes in at least two groups: the main group (patients receiving a new treatment or new drug) and the comparison group (patients not receiving the study drug or taking a known comparator drug). For example, in the study of the effectiveness of the treatment and prevention of coronary heart disease (CHD), the following "end points" are distinguished.

Primary - the main indicators associated with the possibility of increasing the life expectancy of the patient. In clinical studies, these include a reduction in overall mortality, mortality from cardiovascular diseases, in particular myocardial infarction and stroke.

Secondary indicators - reflect an improvement in the quality of life, either due to a decrease in morbidity or alleviation of the symptoms of the disease (for example, a decrease in the frequency of angina attacks, an increase in exercise tolerance).

Tertiary - indicators associated with the possibility of preventing the disease (for example, in patients with coronary artery disease - stabilization of blood pressure, normalization of blood glucose, a decrease in the concentration of total cholesterol, LDL, etc.).

Meta-analysis is a method of searching, evaluating and combining the results of several controlled studies. As a result of meta-analysis, it is possible to establish positive or undesirable effects of treatment that cannot be identified in individual clinical studies. It is necessary that the studies included in the meta-analysis be carefully randomized, their results published with a detailed study protocol, indication of selection and evaluation criteria, and selection of endpoints. For example, two meta-analyses found a beneficial effect of lidocaine on arrhythmia in patients with myocardial infarction, and one found an increase in the number of deaths, which is the most important indicator for evaluating the effect of this drug.

The value of evidence-based medicine in clinical practice. Currently, the concept of evidence-based medicine is widely used when deciding on the choice of drugs in specific clinical situations. Modern guidelines for clinical practice, offering certain recommendations, provide them with a rating of evidence. There is also an international Cochrane initiative (Cochran Library), which unites and systematizes all the information accumulated in this area. When choosing a drug, along with the recommendations of the drug formulary, international or national clinical practice guidelines are used, that is, systematically developed documents designed to facilitate the practitioner, lawyer and patient in making decisions in certain clinical situations. However, studies conducted in the UK have shown that general practitioners are not always inclined to apply national recommendations in their work. In addition, the creation of clear systems of recommendations is criticized by experts who believe that their use limits the freedom of clinical thinking. On the other hand, the use of such guidelines stimulated the abandonment of routine and insufficiently effective methods of diagnosis and treatment, and ultimately increased the level of medical care for patients.

In conclusion, it should be noted that the results of modern clinical studies cannot be considered definitive and absolutely reliable. Obviously, evolutionary leaps in the study of new drugs have occurred and will continue to occur, which leads and will lead to fundamentally new clinical and pharmacological concepts, and hence to new methodological approaches to the study of drugs in clinical trials.

BASICS RATIONAL PHARMACOTHERAPY

Pharmacotherapy is one of the main methods of conservative treatment. Modern pharmacotherapy is a rapidly developing area of ​​clinical medicine and is developing a scientific system for the use of drugs. Pharmacotherapy is based mainly on clinical diagnostics and clinical pharmacology. The scientific principles of modern pharmacotherapy are formed on the basis of pharmacology, pathological physiology, biochemistry, as well as clinical disciplines. The dynamics of the symptoms of the disease in the course of pharmacotherapy can be a criterion for clinical assessment of the quality and degree of the achieved pharmacological effect.

Basic principles of pharmacotherapy

Pharmacotherapy should be effective, i.e., provide a successful solution of the set goals of treatment in certain clinical situations. The strategic goals of pharmacotherapy can be different: cure (in the traditional sense), slow down the development or relief of exacerbation, prevent the development of the disease (and its complications), or eliminate painful or prognostically unfavorable symptoms. In chronic diseases, medical science has identified the main goal of treating patients with disease control with a good quality of life (i.e. subjectively good condition of the patient, physical mobility, absence of pain and discomfort, ability to serve oneself, social activity).

One of the main principles of modern pharmacotherapy, carried out by highly active drugs acting on various body functions, is the safety of treatment.

The principle of minimizing pharmacotherapy involves the use of a minimum amount of drugs to achieve a therapeutic effect, i.e. limiting pharmacotherapy only to the amount and duration of drug use, without which treatment is either impossible (not effective enough), or requires the use of more “dangerous” methods than pharmacotherapy. treatment. This principle implies the rejection of unreasonable polypharmacy and polytherapy. The implementation of this principle is facilitated by a correct assessment of the possibility of partial replacement of pharmacotherapy with other methods of treatment (for example, balneo-, climate-, psycho-, physiotherapy, etc.).

The principle of rationality implies the optimal ratio of efficacy and safety of pharmacotherapy, which ensures the maximum possible therapeutic effect with the lowest risk of developing undesirable effects. When indications for the combined use of several drugs, the principle of rationality involves a medical assessment of the comparative significance of efficacy and safety in order to limit the number of prescribed drugs. Possible contraindications to pharmacotherapy are also assessed, including lack of diagnosis (eg, abdominal pain) and incompatibility of drug and non-drug treatments (eg, defibrillation for cardiac arrhythmia after prior use of cardiac glycosides). In some cases, the ambiguity of the diagnosis, on the contrary, may be an indication for pharmacotherapy for the diagnosis of exjuvantibus. The principle of economical pharmacotherapy is used in cases where the possibility of etiotropic or pathogenetic therapy excludes (or minimizes) the need for the use of symptomatic agents or drugs that act on secondary links of pathogenesis.

The controllability of pharmacotherapy provides for continuous medical analysis and evaluation of both expected and unforeseen results of drug use. This allows you to timely make adjustments to the chosen treatment tactics (change in dose, route of administration of drugs, replacement of a drug that is ineffective and / or caused side effects with another, etc.). Compliance with this principle is based on the use of objective criteria and methods for assessing the quality and degree of the therapeutic effect, as well as early detection of unwanted and side effects of drugs. The principle of individualization of pharmacotherapy is not always feasible, therefore, the development of scientific prerequisites for its approval is one of the main tasks of clinical pharmacology. The practical implementation of the principle of individualization of pharmacotherapy characterizes the highest level of mastery of the method of pharmacotherapy. It depends on the qualifications of the specialist, providing him with complete and reliable information about the action of the drug, as well as the availability of modern methods for monitoring the functional state of organs and systems, as well as the action of the drug.

Types of pharmacotherapy

There are the following types of pharmacotherapy:

1. Etiotropic (elimination of the cause of the disease).

2. Pathogenetic (influencing the mechanism of the development of the disease).

3. Substitutive (compensation for a lack of vital substances in the body).

4. Symptomatic (elimination of individual syndromes or symptoms of the disease).

5. Restorative (restoration of broken parts of the body's adaptive system).

6. Preventive (prevention of the development of an acute process or exacerbation of a chronic one).

In an acute disease, treatment most often begins with etiotropic or pathogenetic pharmacotherapy. In case of exacerbation of chronic diseases, the choice of the type of pharmacotherapy depends on the nature, severity and localization of the pathological process, the age and sex of the patient, the state of his compensatory systems, in most cases, treatment includes all types of pharmacotherapy.

The successes of pharmacotherapy in recent years are closely related to the development of the principles and technologies of evidence-based medicine (see the chapter "Clinical drug trials. Evidence-based medicine"). The results of these studies (level of evidence A) contribute to the introduction into clinical practice of new technologies aimed at slowing down the development of the disease and delaying severe and fatal complications (for example, the use of β-blockers and spironolactone in chronic heart failure, inhaled glucocorticoids in bronchial asthma, ACE inhibitors in diabetes, etc.). The evidence-based indications for long-term and even lifelong use of drugs were also expanded.

The relationship between clinical pharmacology and pharmacotherapy is so close that it is sometimes difficult to draw a line between them. Both are based on general principles, have common goals and objectives, namely: effective, competent, safe, rational, individualized and economical therapy. The difference is that pharmacotherapy determines the strategy and goal of treatment, while clinical pharmacology provides tactics and technology to achieve this goal.

Goals and objectives of rational pharmacotherapy

Rational pharmacotherapy of a particular patient includes the following tasks:

Definition of indications for pharmacotherapy and its purpose;

Choice of drugs or combinations of drugs;

The choice of routes and methods of administration, as well as forms of release of drugs;

Determination of the individual dose and dosing regimen of drugs;

Correction of drug dosing regimens during treatment;

Selection of criteria, methods, means and timing of pharmacotherapy control;

Justification of the timing and duration of pharmacotherapy;

Determination of indications and technology of drug withdrawal.

What is the starting point for pharmacotherapy?

Before starting pharmacotherapy, the need for it should be determined.

If intervention during the course of the disease is necessary, the drug can be prescribed, provided that the likelihood of its therapeutic effect is greater than the likelihood of undesirable consequences of its use.

Pharmacotherapy is not indicated if the disease does not change the quality of life of the patient, its predicted outcome does not depend on the use of drugs, and also if non-drug methods of treatment are effective and safe, more preferable or inevitable (for example, the need for emergency surgery).

The principle of rationality underlies the construction of pharmacotherapy tactics in a specific clinical situation, the analysis of which makes it possible to substantiate the choice of the most adequate drugs, their dosage forms, doses and routes of administration, and (presumably) the duration of use. The latter depends on the expected course of the disease, the pharmacological effect, the likelihood of drug dependence.

The goals and objectives of pharmacotherapy largely depend on its type and may differ in etiotropic and pathogenetic treatment.

For example, the goal and task of symptomatic pharmacotherapy in an acute situation are usually the same - easing painful symptoms, pain relief, lowering body temperature, etc.

In pathogenetic therapy, depending on the course of the disease (acute, subacute or chronic), the tasks of pharmacotherapy can vary significantly and determine different technologies for the use of drugs. Thus, the task of pharmacotherapy in hypertensive crisis is to quickly relieve its symptoms and reduce the likelihood of complications under the control of clinical symptoms and reduce blood pressure to the required levels. Therefore, drugs or a combination of drugs are used in the "pharmacological test" technology (see below). With severe and persistent arterial hypertension, a stepwise decrease in blood pressure can be carried out, and the immediate goal of pathogenetic therapy will be to eliminate the symptoms of the disease, and the strategic goal will be to prolong the life of the patient, ensure quality of life, and reduce the risk of complications. During pathogenetic therapy, various technologies are used to provide individualized pharmacotherapy.

Stages of rational pharmacotherapy

The tasks of pharmacotherapy are solved in several stages.

At the first stage, the choice of drugs is usually carried out according to the underlying disease (syndrome). This stage includes determining the goals and objectives of treating a particular patient, taking into account the nature and severity of the disease, the general principles of its treatment, and possible complications of previous therapy. Take into account the prognosis of the disease and the features of its manifestation in a particular patient. It is very important for the effectiveness and safety of pharmacotherapy to determine the degree of functional disorders in the body and the desired level of their recovery.

For example, in a hypertensive crisis in a patient with previously normal blood pressure values, the desired effect is normalization of blood pressure within 30-60 minutes, and in a patient with stable arterial hypertension, a decrease in blood pressure to the levels to which he is adapted. When removing a patient from acute pulmonary edema, the task of achieving the necessary diuretic effect (1 liter of urine for 1 hour) can be set.

In the treatment of subacute and chronic diseases, the desired result may be different at different stages of therapy.

It is more difficult to choose control parameters during the "metabolic" type of therapy. In these cases, the evaluation of the action of drugs can be carried out indirectly using evidence-based medicine or meta-analysis techniques. For example, in order to prove the effectiveness of trimetazidine in the treatment of coronary artery disease, it was necessary to conduct a multicenter prospective study and evaluate the feasibility of prescribing it, showing a decrease in the incidence of coronary artery disease complications in the study group compared to the control group.

At the first stage, based on the characteristics of the course of the disease (syndrome) and the degree of functional disorders, the main pathophysiological links, the intended targets and mechanisms of drug action, i.e. the spectrum of necessary pharmacodynamic effects of drugs in a particular patient, are determined. Also, the desired (or necessary) pharmacokinetic parameters of the drug and the required dosage form are determined. Thus, a model of the optimal drug for a particular patient is obtained.

The second stage includes the selection of a pharmacological group or groups of drugs, taking into account their mechanism of action and pharmacological properties. The choice of a specific drug depends on its mechanism of action, bioavailability, distribution in tissues and elimination, as well as the availability of the required dosage forms.

The third stage is the choice of a specific drug, determining its dose, frequency of administration and methods for monitoring its effectiveness and safety. The selected drug should correspond to the "optimal" (or approach it).

The fourth stage is a correction in ongoing pharmacotherapy due to its ineffectiveness, the appearance of new symptoms or complications of the disease, or the achievement of a predictable stabilization of the patient's clinical condition.

If therapy is ineffective, it is necessary to prescribe drugs with a different mechanism of action or combinations of drugs. It is necessary to predict and detect a decrease in the effect of some drugs due to tachyphylaxis, induction of liver enzymes, the formation of AT to drugs, etc. doses (for example, clonidine), the appointment of another drug or combination of drugs.

When the patient's condition stabilizes, either the drug should be canceled or it should be prescribed as maintenance therapy. With the abolition of certain drugs (for example, antidepressants, anticonvulsants, clonidine, methyldopa, p-blockers, slow calcium channel blockers, histamine H 2 receptor blockers, systemic glucocorticoids), the dose should be reduced gradually.

Pharmacological history

At the 2nd and 3rd stages of pharmacotherapy, a carefully and purposefully collected pharmacological history is essential for decision making. The information obtained makes it possible to avoid mistakes (sometimes irreparable) in the presence of drug intolerance, to get an idea of ​​the effectiveness or inefficiency of previously used drugs (and sometimes about the reason for low efficiency or developed adverse reactions). For example, adverse drug reactions characteristic of an overdose of theophylline (nausea, vomiting, dizziness, anxiety), when a patient used teopak at a dose of 300 mg, were caused by the fact that the patient carefully chewed the tablets and washed them down with water, which changed the kinetics of the prolonged form of the drug and led to to create a high peak concentration of theophylline in the blood.

Pharmacological history can have a significant impact on the choice of the primary drug or its initial dose, change the tactics of drug therapy. For example, the lack of effect of enalapril 5 mg in the past on arterial hypertension in a patient with type 2 diabetes mellitus suggests the need for a higher dose of the drug. The mention of the “escape” of the diuretic effect of furosemide during long-term use in a patient with chronic heart failure determines the advisability of additionally prescribing a potassium-sparing diuretic or potassium preparations. The ineffectiveness of inhaled glucocorticoids in a patient with bronchial asthma may be the result of a violation of the inhalation technique.

Choice of drug and dosage regimen

In recent years, treatment often begins with regulated drugs. Regulated drugs of first choice for many common diseases are well known and generally prescribed. The drug of first choice is included in the state list of vital drugs, is available in the formulary of the medical institution and is offered in approved standard treatment regimens for the category of patients under consideration. For example, if the “optimal” drug determined by the doctor approaches the regulated drug in terms of pharmacodynamic and pharmacokinetic parameters, the latter may become the drug of first choice.

The 3rd stage of pharmacotherapy is complicated, there are different options for solving its problems. So, when a history of intolerance or a significant lack of effect is indicated when using a regulated drug, another drug is chosen that corresponds to the “optimal” one. It may also be a regulated drug, but in a particular clinical situation it may be necessary to choose a non-standard drug.

After choosing a drug, it is necessary to clarify information about the onset and time of development of its maximum effect, all pharmacological effects, and be sure to correlate the risk of developing undesirable effects with concomitant diseases in a particular patient. After that, already at this stage, sometimes it is necessary to abandon the use of the selected drug. For example, if there are all indications for the use of nitrates in a patient, they are not prescribed for concomitant glaucoma or increased intracranial pressure.

Treatment usually begins with a regulated average dose and the recommended regimen for taking the drug (taking into account the route of administration). When determining the individual dose of the drug, they proceed from the idea of ​​​​its average dose, i.e., the dose that provides therapeutic drug concentrations in the body with the chosen route of administration in most patients. The individual dose is defined as the deviation from the average required for a particular case. The need to reduce the dose arises in connection with age-related changes, in violation of the functions of organs involved in the elimination of drugs, homeostasis disorders, changes in the sensitivity of receptors in target organs, individual hypersensitivity, etc.

The drug in doses exceeding the average is prescribed with a decrease in the bioavailability of drugs, low sensitivity of the patient to it, as well as the use of drugs that weaken its effects (antagonists or accelerate biotransformation or excretion). An individual dose of a drug may differ significantly from that indicated in reference books and guidelines. In the process of using drugs, the dose is adjusted.

Taking into account the purpose and depending on the duration of the action of the administered drug, a single, daily, and sometimes course dose is determined. Doses of drugs that are characterized by material or functional cumulation may be different at the beginning of treatment (initial, saturating dose) and during its continuation (maintenance dose). For such drugs (for example, cardiac glycosides, amiodarone), various initial dosing schemes are being developed, providing for a different rate of onset of the effect depending on the rate of saturation. When determining a single dose, the criterion for its adequacy is the required therapeutic effect in the expected duration of the drug after its single administration.

An individual drug dosing regimen should be developed in accordance with chronopharmacology, which increases the effectiveness and safety of pharmacotherapy. Chronopharmacological technology that increases the effectiveness of pharmacotherapy is preventive chronotherapy, which takes into account the time of onset of the maximum deviation of a particular function from normal values ​​and the pharmacokinetics of the corresponding drugs. For example, the appointment of enalapril to a patient with arterial hypertension 3-4 hours before the "usual" maximum increase in blood pressure will increase the effectiveness of antihypertensive therapy. A chronopharmacological approach that takes into account biological rhythms underlies the administration of the entire daily dose of systemic glucocorticoids in the morning to reduce the risk of secondary adrenal insufficiency.

The dosing regimen of drugs can be standard, corresponding to the instructions for use. Correction of the dosing regimen is carried out with the peculiarities of the course of the disease, as well as in accordance with the results of the pharmacological test. In some cases, dose titration is used, i.e., a slow, stepwise increase in an individual tolerated dose with strict objective control of predicted adverse reactions and pharmacodynamic effects (for example, dose selection of a p-blocker in chronic heart failure).

The concept of a pharmacological test

A drug test, or pharmacological test, is an assessment of the patient's individual response to the first use of drugs. This is an important technological technique used in pharmacotherapy to individualize treatment. The test allows you to determine the degree and reversibility of functional disorders, the tolerance of the selected drug and, in many cases, predict the clinical effect, as well as determine the dosing regimen (especially if there is a correlation between the first effect of the drug and its subsequent effect).

Pharmacological tests are used in functional diagnostics, for example, stress echocardiography with dobutamine - to verify the diagnosis of coronary artery disease and study the state of viable myocardium in patients with chronic heart failure, echocardiography with a nitroglycerin test - to detect the reversibility of restrictive diastolic dysfunction of the left ventricle; ECG with atropine test - for the differential diagnosis of bradycardia of functional or organic origin; function of external respiration (RF) with a test with p 2 -agonist - to detect the reversibility of bronchial obstruction.

The use of drugs in an acute clinical situation can also be considered a pharmacological test (the doctor evaluates the effectiveness and safety of drugs). For example, with intravenous administration of furosemide, it is necessary to control not only the amount of urine excreted, but also blood pressure due to the risk of developing severe arterial hypotension.

Conducting a test includes dynamic monitoring of indicators that reflect the functional state of the system, which is affected by the selected drug. The study is first carried out at rest before meals (it is possible with physical or other exertion), and then after taking the drug. The duration of the study is determined by the pharmacodynamic, pharmacokinetic properties of the drug and the patient's condition.

A pharmacological test is carried out with drugs that are characterized by the effect of the "first dose" and / or the relationship between blood concentration and potency. The test is ineffective when using JIC with a long latent period for the development of the effect.

When conducting a pharmacological test, it is necessary to choose objective and accessible control methods that correspond to the objectives of the study.

Efficacy and safety control during pharmacotherapy

In order to choose objective and affordable control methods and determine the frequency of their implementation during course pharmacotherapy, it is necessary to answer the following questions.

What are the criteria characterizing the stabilization of the condition in this patient?

What are the parameters whose dynamics reflects the efficacy and safety of the selected drug?

How long after taking the drug should we expect changes in the controlled parameters?

When can the maximum therapeutic effect be expected?

When can stabilization of clinical indicators occur?

What are the criteria for dose reduction or discontinuation of the medicinal product due to the clinical effect obtained?

Changes in what indicators may indicate the "escape" of the effect of the therapy?

The dynamics of what parameters reflects the possibility of side effects of the drug used?

After what period of time after taking the drug is it possible to develop the predicted side effects and what aggravates their manifestation?

The answers to the questions posed should be contained in the program of pharmacotherapy for each patient. It includes mandatory and optional research methods, determination of their frequency and sequence, application algorithm.

In some cases, continuous monitoring of changes in key indicators during drug therapy is absolutely necessary, and the inability to conduct it may

serve as a contraindication to the appointment of drugs (for example, an antiarrhythmic drug for complex cardiac arrhythmias in the absence of ECG monitoring methods).

When conducting drug therapy for chronic diseases, even if the patient receives only preventive therapy and is in remission, the examination should be carried out at least once every 3 months.

Particular attention is paid to the dosing regimen during long-term therapy with drugs with a small therapeutic latitude. Only drug monitoring can avoid severe adverse reactions.

Clinical criteria for the effectiveness of the drug can serve as the dynamics of the patient's subjective sensations (for example, pain, itching, thirst, sleep quality, shortness of breath) and objective signs of the disease. The definition of objective criteria is desirable even when using drugs, the effect of which is assessed mainly subjectively (for example, analgesics, antidepressants). Reduction of any symptom of the disease may be accompanied by an increase in the patient's functionality (for example, an increase in the range of motion in the affected joint after taking an analgesic, a change in behavior after the use of antidepressants), which can be detected using objective tests.

Patient adherence to treatment

The patient's adherence to treatment, or compliance (from the English compliance - consent), implies the conscious participation of the patient in the selection and self-control of pharmacotherapy. The main factors that adversely affect patient adherence to treatment are as follows:

Misunderstanding of the patient's instructions given by the doctor;

Low level of education of the patient;

Elderly age;

mental illness;

Complex scheme for taking drugs;

Appointment of a large number of drugs at the same time;

Lack of patient confidence in the doctor;

Irregular visits to the doctor;

Patients do not understand the severity of their condition;

Memory disorders;

Improving the patient's well-being (may prematurely stop treatment or change the drug regimen);

Development of unwanted drug reactions;

Distorted information about drugs received at the pharmacy, from relatives, acquaintances;

Poor financial situation of the patient. Unsatisfactory patient adherence to treatment (for example, unauthorized drug withdrawal) can lead to adverse drug reactions, up to severe, life-threatening complications. No less dangerous is the unauthorized change in the dosing regimen of JIC, as well as the independent inclusion of other drugs in the treatment regimen.

What should the doctor do to improve the patient's adherence to treatment?

Clearly name LS.

Clearly explain the purpose of taking drugs.

Indicate the expected time of the expected effect.

Give instructions in case of missing the next drug intake.

Inform about the duration of treatment.

Explain what adverse drug reactions may develop.

Caution if JIC affects physical and mental activity.

Indicate the possible interaction of drugs with alcohol, food, smoking.

Elderly patients and those with memory impairment should be given written instructions about the entire pharmacotherapy regimen. The same category of patients can be recommended to place drugs in advance in containers (jars, boxes, paper or plastic bags, etc.) with the indicated time of admission. Promising areas for increasing patient adherence to treatment are the development of educational programs for patients with bronchial asthma, diabetes mellitus, peptic ulcer and other diseases. Self-monitoring of treatment using individual monitoring devices (peak flow meters, glucometers, blood pressure, heart rate monitoring devices, etc.) contributes to timely self-correction of treatment and timely access to a doctor. The analysis of the treatment control diaries submitted to the patient contributes to the improvement of the quality of individualized therapy.

Pharmacotherapy of emergency conditions

Of particular difficulty for the doctor is the pharmacotherapy of emergency conditions, when the patient may develop paradoxical reactions to administered drugs and increase the risk of their side effects. In emergency conditions, the doctor needs promptness in choosing a drug and using it in adequate doses, taking into account possible drug interactions.

The choice of drug and its dose depends on the specific clinical situation and the dynamics of the main functional indicators of the patient. Thus, the goal of pharmacotherapy for acute pulmonary edema is the rapid elimination of left ventricular overload; depending on the severity of the patient's condition, the pathogenesis of edema, central and peripheral hemodynamics, drugs with various pharmacodynamic effects can be used: drugs with a positive inotropic effect, vasodilators that reduce preload (nitrates, enalapril), antiarrhythmic drugs, diuretics, or a combination of these drugs. The selected drug should be water-soluble, have a short T]/2, be produced in ampoules.

Long-term pharmacotherapy

With long-term pharmacotherapy, a change in the patient's condition can be associated both with the course of the disease and with the ongoing pharmacotherapy. When it is carried out, the following situations may occur.

An increase in the concentration of drugs in the blood due to changes in its pharmacokinetic parameters and / or accumulation of active metabolites. This causes an increase in the pharmacological effect and increases the likelihood of side effects. In this case, the dose of the drug should be reduced or it should be canceled.

Restoration of disturbances in the regulation of body functions, increased compensatory reactions, which can enhance the pharmacological effect at the same concentration of drugs in the blood. And in this case, you should reduce the dose of drugs or cancel it.

A decrease in the clinical efficacy of a drug, associated either with a decrease in its concentration in the blood, or, for example, with a decrease in the sensitivity and / or density of receptors (for example, weakening the effects of β-agonists in bronchial asthma). It is possible to differentiate the cause of the “escape” of the drug effect and choose a therapeutic tactic only after determining its C ss in the blood: if it is reduced, the dose should be increased, and if it corresponds to the therapeutic one, it is necessary to replace the drug with another one with a different mechanism of action.

In some cases, there is a need for long-term (sometimes lifelong) maintenance pharmacotherapy.

If the drug serves as a means of replacement therapy (for example, an insulin preparation for type I diabetes mellitus).

In the formation of a drug-dependent course of the disease with a threat of death when the drug is discontinued (for example, glucocorticoids in the hormone-dependent variant of bronchial asthma).

When correcting persistent functional disorders that significantly affect the quality of life of the patient and the prognosis of the disease (for example, the use of ACE inhibitors in chronic heart failure).

Errors in evaluating the effect of drugs

Errors in assessing the action of the drug are most often associated with the fact that the doctor does not take into account that the developing changes in the patient's condition, expected from the action of the drug, are not always the result of its pharmacological action. They can also be caused by the following factors:

Psychotherapeutic action (similar to the placebo effect);

An effect caused by another drug (for example, the disappearance of ventricular extrasystoles when using an antianginal drug that does not have antiarrhythmic activity);

Spontaneous restoration of impaired function or weakening of the manifestations of the pathological process due to the onset of recovery or the cessation of exposure to pathogenic factors.

An adequate assessment of the relationship between signs of improvement in the patient's condition and the action of drugs allows you to timely cancel unnecessary drugs or replace them with more effective ones.

Timely cancellation of drugs is the last, very important stage of pharmacotherapy. The following justifications for the abolition of drugs or their combinations are possible.

Achieving the goal of pharmacotherapy, i.e. stopping the pathological process or restoring the function, the violation of which served as the basis for prescribing the drug.

Weakening or disappearance of the therapeutic effect, which may be due to the peculiarities of the pharmacological action of the drug or the formation of irreversible changes in target organs.

The predominance of contraindications over indications for the use of drugs as a result of the development of a pathological process or an increase in the risk of dangerous consequences of the drug. (A special case of such justification is the completion of a course of taking drugs with a regulated course dose or duration of use.)

The manifestation of a toxic or side effect of a drug, excluding the possibility of replacing it with a drug of a similar effect (for example, digitalis intoxication is an absolute contraindication to the use of all cardiac glycosides).

Cancellation of drugs is contraindicated if it serves as the only factor in maintaining the vital functions of the body, or if it is canceled, decompensation of functions that ensure the patient's adaptation to the environment is possible.

With indications for drug withdrawal and the absence of contraindications to it, the doctor determines the necessary rate of drug withdrawal, taking into account the changes in the body caused by it. This provision applies primarily to hormonal drugs and drugs that affect neurotransmitter systems (for example, with a sharp abolition of glucocorticoids, adrenal insufficiency may develop, with a sudden abolition of clonidine - severe hypertensive crises).

The following options for canceling drugs are possible, depending on the likelihood of developing a withdrawal syndrome.

Stopping the use of drugs is possible for the vast majority of drugs with their short-term use.

Gradual decrease in the daily dose. The duration of this stage depends on the time required to restore the functional changes caused by the drug (for example, increased sensitivity of adrenoreceptors when taking sympatholytics or suppressed function of the adrenal cortex with long-term use of glucocorticoids).

Cancellation of drugs "under the guise" of another drug that prevents the development of undesirable consequences of withdrawal (for example, the abolition of clonidine against the background of p-blockers or other antihypertensive drugs).

Combined use of drugs

Indications for complex pharmacotherapy can be either the presence of two or more different pathological processes in a patient, each of which requires drug treatment, or a disease in which etiotropic, pathogenetic and / or symptomatic pharmacotherapy is indicated.

The goals of the combined use of drugs are to enhance the therapeutic effect (with insufficient effectiveness of one drug), reduce the dose of the drug to reduce its toxic or undesirable effects, or neutralize the undesirable effect of the main drug (see the chapter "Drug Interactions").

The combined use of drugs is also carried out in accordance with the above general principles of pharmacotherapy based on the results of studying the mechanisms of interaction of drugs, analyzing the pathogenesis of the disease and its manifestations in a particular patient, assessing the degree of functional disorders, the presence of concomitant diseases, the nature of the course of the disease and other factors.

MEDICINAL DRUGS INCREASING VASCULAR TONE

Drugs that increase vascular tone are divided into the following groups.

1. LS central action.

Psychostimulants.

Analeptics.

Tonic drugs.

2. Drugs that stimulate the peripheral nervous system.

Stimulants of a- and (3-adrenergic receptors: epinephrine, ephedrine, dephedrine.

Stimulants predominantly a-adrenergic receptors: norepinephrine, phenylephrine, etaphedrine, midodrine.

Stimulants of dopamine, a- and (3-adrenergic receptors: dopamine.

3. Drug predominantly myotropic action: angiotensinamide. Centrally acting drugs are not considered in this section, since an increase in vascular tone is not considered their main pharmacological effect.

Date added: 2015-02-06 | Views: 3387 | Copyright infringement

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1. Clinical trials of medicinal products for medical use, including international multicenter, multicenter, post-registration, are conducted in one or more medical organizations in accordance with the rules of good clinical practice approved by the authorized federal executive body, respectively, for the following purposes:

1) establishing the safety of medicinal products for healthy volunteers and (or) their tolerance by healthy volunteers, with the exception of such studies of medicinal products manufactured outside the Russian Federation;

3) establishing the safety of the medicinal product and its effectiveness for patients with a certain disease, the prophylactic effectiveness of immunobiological medicinal products for healthy volunteers;

4) studying the possibility of expanding indications for medical use and identifying previously unknown side effects of registered drugs.

2. With respect to generic medicinal products for medical use, bioequivalence and (or) therapeutic equivalence studies are carried out in accordance with the procedure established by the authorized federal executive body.

3. The organization of conducting clinical trials of a medicinal product for medical use may be carried out by:

1) the developer of the medicinal product or a person authorized by him;

2) educational organizations of higher education, organizations of additional professional education;

(see text in previous edition)

3) research organizations.

4. Clinical trials of a medicinal product for medical use are conducted on the basis of a permit to conduct a clinical trial of a medicinal product issued by the authorized federal executive body. The authorized federal executive body maintains a register of issued permits for conducting clinical trials of a medicinal product, containing an indication of their purpose or purposes, in the manner prescribed by this body.

(see text in previous edition)

(see text in previous edition)

6. The developer of a medicinal product may involve legal entities of any legal form in organizing clinical trials of a medicinal product for medical use, provided that these trials comply with the requirements of this Federal Law.

7. Clinical trials of medicinal products for medical use are carried out in medical organizations accredited by the authorized federal executive body in the manner established by the Government of the Russian Federation.

8. The list of medical organizations that have the right to conduct clinical trials of medicinal products for medical use and the register of issued permits to conduct clinical trials of medicinal products are published and posted by the authorized federal executive body in the manner prescribed by it on its official website on the Internet.

Planning and conducting clinical trials of medicines. Protection of the rights of the subjects. Informed consent of the subjects. Ethics committee approval. Mandatory patient insurance. Completed by: Student of group 110 Sannikova A.A.

Planning and conducting clinical trials of drugs. Clinical trials of a drug are a necessary step in the development of any new drug, or expansion of indications for the use of a drug already known to doctors.

At the initial stages of drug development, chemical, physical, biological, microbiological, pharmacological, toxicological and other studies are carried out on tissues (in vitro) or on laboratory animals. These are the so-called preclinical studies, the purpose of which is to obtain, by scientific methods, assessments and evidence of the effectiveness and safety of medicines. However, these studies cannot provide reliable information about how the studied drugs will act in humans, since the body of laboratory animals differs from the human body both in terms of pharmacokinetic characteristics and in the response of organs and systems to drugs. Therefore, it is necessary to conduct clinical trials of drugs in humans.

So, what is a clinical study (test) of a drug? This is a systematic study of a medicinal product through its use in a person (patient or healthy volunteer) in order to assess its safety and efficacy, as well as to identify and confirm its clinical, pharmacological, pharmacodynamic properties, assessment of absorption, distribution, metabolism, excretion and / or interaction with other medicines.

Participants in a Clinical Trial The decision to start a clinical trial is made by the Sponsor/Customer, who is responsible for the organization, control and financing of the trial. The responsibility for the practical conduct of the study rests with the Researcher (a person or group of persons). As a rule, the sponsors are pharmaceutical companies - drug developers, however, the researcher can also act as a sponsor if the study was initiated on his initiative and he bears full responsibility for its conduct.

Clinical trials must be conducted in accordance with the fundamental ethical principles of the Declaration of Helsinki, the Nuremberg Code, GСP (Good Clinical Practice) Rules and applicable regulatory requirements. Prior to the start of a clinical trial, an assessment should be made of the relationship between the foreseeable risk and the expected benefit for the subject and society. At the head is the principle of priority of the rights, safety and health of the subject over the interests of science and society. The subject can be included in the study only on the basis of voluntary informed consent obtained after a detailed acquaintance with the study materials.

The clinical trial must be scientifically justified and described in detail and clearly in the study protocol. Assessment of the balance of risks and benefits, as well as review and approval of the study protocol and other documentation related to the conduct of clinical trials, are the responsibilities of the Expert Council of the Organization / Independent Ethics Committee (IEC / IEC). Once approved by the IRB/IEC, the clinical trial can proceed.

The reliability of clinical trial results depends entirely on how carefully they are planned, conducted, and analyzed. Any clinical trial should be carried out according to a strictly defined plan (research protocol), which is identical for all medical centers participating in it. The study protocol includes a description of the purpose and design of the study, criteria for inclusion (and exclusion) in the trial and evaluation of the effectiveness and safety of the treatment, treatment methods for study subjects, as well as methods and timing for evaluating, recording and statistical processing of efficacy and safety indicators.

The objectives of the test must be clearly stated. Regardless of the goal, it is necessary to clearly articulate what end result will be quantified. GCP rules do not allow the use of material incentives to attract patients to participate in the study (with the exception of healthy volunteers involved in the study of pharmacokinetics or bioequivalence of drugs). The patient must meet the exclusion criteria.

Usually, pregnant women, breastfeeding patients, patients with severely impaired liver and kidney function, aggravated by an allergic history are not allowed to participate in studies. Incapacitated patients are not allowed to be included in the study without the consent of the trustees, as well as military personnel and prisoners. Clinical trials in juvenile patients are performed only when the investigational drug is intended exclusively for the treatment of childhood diseases or the study is conducted to obtain information about the optimal dosage of the drug for children. Usually, patients with a certain risk of adverse reactions are excluded from the study, for example, patients with bronchial asthma, etc.

The safety of drugs is assessed throughout the study by analyzing physical data, anamnesis, performing functional tests, ECG, laboratory tests, measuring pharmacokinetic parameters, recording concomitant therapy, as well as side effects. Information about all adverse reactions noted during the study should be entered in the individual registration card and the adverse event card. Adverse event - any undesirable change in the patient's condition, different from the state before the start of treatment, related or not related to the study drug or any other drug used in concomitant drug therapy.

Protection of the rights of the subjects. In any clinical trial, the rights of the subjects must be respected. Rights in Russia are guaranteed by: the Constitution, Federal Law No. 323 “On the Fundamentals of Health Protection in the Russian Federation”, the Helsinki Declaration, the Nuremberg Code and international law,

In the Constitution of the Russian Federation, Art. 21 states: “No one shall be subjected to torture, violence, other cruel or degrading treatment or punishment. No one can be subjected to medical, scientific or other experiments without voluntary consent. » Any study is conducted with the voluntary informed consent of the subjects. This is reflected in Art. 20 Federal Law No. 323 "On the basics of health care in the Russian Federation"

article 20 the risks associated with them, possible options for medical intervention, its consequences, as well as the expected results of medical care.

Informed voluntary consent to medical intervention is given by one of the parents or other legal representative, if the person is not legally capable. A citizen, one of the parents or other legal representative of the person has the right to prevent interference. But in case of refusal in an accessible form, the possible consequences of such a refusal should be explained, and also that the medical organization has the right to go to court to protect the interests of such a person.

Informed voluntary consent to medical intervention or refusal of medical intervention is drawn up in writing, signed by a citizen, one of the parents or other legal representative, a medical worker and is contained in the patient's medical records. Compulsory medical measures may be applied to persons who have committed crimes on the grounds and in the manner established by federal law.

Medical intervention without the consent of a citizen, one of the parents or other legal representative is allowed: 1) if medical intervention is necessary for emergency reasons to eliminate the threat to a person's life and if his condition does not allow him to express his will. 2) in relation to persons suffering from diseases that pose a danger to others; 3) in relation to persons suffering from severe mental disorders; 4) in relation to persons who have committed socially dangerous acts; 5) during the conduct of a forensic medical examination and (or) a forensic psychiatric examination.

Ethics committee approval. “The Ethics Committee is an independent body (institutional, regional, national, or supranational) composed of individuals with and without a scientific/medical background whose responsibilities include protecting the rights, safety, and well-being of research subjects and safeguarding the public this protection through review and approval of the clinical trial protocol, the acceptability of investigators, equipment, and the methods and materials that are intended to be used in obtaining and documenting the informed consent of research subjects.

To conduct a multicenter clinical trial (CT), permission from the Russian Ministry of Health and Social Development is required. But first you need to get the opinion of the expert council and the approval of the ethical committee at the same body, and then the approval of clinical trials in the local ethical committees (LEC) of the selected bases.

CT, the subject of which is related to the use of drugs, methods of diagnostics and treatment in humans, should be checked for compliance with international and Russian legislative acts and ethical principles of biomedical research in humans. When planning a clinical trial involving a person as an object of study, the applicant for a scientific degree must be strictly guided by the normative and regulatory documentation of the Ministry of Health of Russia, as well as obtain written informed consent from the persons participating in the study, or their legal representatives, and approval to conduct the study by an independent LEK. Without compliance with all the above requirements, CT cannot be conducted.

Compulsory patient insurance The contract of compulsory life and health insurance for patients participating in clinical trials of medicinal products protects the property interests of the insured organization and insured persons. The program of compulsory life and health insurance for patients participating in clinical trials of a medicinal product provides protection against the risks associated with the death and deterioration of the health of the insured persons.

The insurer pays 2 million rubles in the event of the death of the insured person as a result of participation in drug trials. Compensation is paid to beneficiaries. The insurance company compensates the insured person for financial losses associated with the deterioration of health, which led to the establishment of disability. The amount of compensation is 1.5 million rubles for group I disability, 1 million rubles for group II disability, and 500,000 rubles for group III disability. The insurer also compensates the patient for losses associated with the deterioration of health, which did not lead to the establishment of disability. In this case, the amount of compensation is up to 300,000 rubles.

The procedure for drawing up an insurance contract for conducting clinical trials. The contract is concluded on the basis of the "Application for insurance". The Application specifies the maximum number of patients (based on which the insurance premium is calculated under the contract), the name of the medicinal product, the objectives of the clinical trial, the name of the clinical trial protocol.

Stages of concluding an insurance contract 1. The parties sign a Confidentiality Agreement (at the request of the Insured). 2. The insured provides the "Clinical Research Protocol" and the "Application for Insurance", indicating the maximum number of patients participating in the research. 3. RESO-Garantia prepares a set of documents and sends the electronic version to the Policyholder for approval. 4. The parties sign the insurance contract and exchange original documents. 5. The policyholder pays the insurance premium. 6. The insured provides identification codes of patients (as soon as consent to a clinical trial is obtained). 7. The Guarantee draws up policies for each Insured, patient and researcher leaflets.

Very negative? After all, some tools really help. The disadvantage of folk remedies is that the effectiveness of most of them is not tested by strict scientific methods, so there is always a big risk of error. But there is another effect placebo”- self-hypnosis, when the patient convinces himself that the medicine really helps, although it can be ordinary tap water.

Last time I talked about what clinical trials of drugs are like, and today I will focus on the technique of conducting them and evaluating the results.

What is the GCP protocol

With regard to the production of medicines, there is an international GMP standard(good manufacturing practice - good manufacturing practice), and for clinical trials of drugs was created GCP standard(good clinical practice - good clinical practice).

Each patient participating in the trials must give written consent to treatment with the possible use of a placebo. Do they pay him? Usually not. The patient simply receives free treatment. The study protocol for a new drug must be approved ethics committee each hospital where the trials are being conducted. Why is it necessary? There is a fine line here. The doctor has no right to use a placebo in seriously ill patients if this could end tragically (for example, in the case of appendicitis the doctor is obliged to prescribe an operation to the patient, although there have been no comparative clinical studies on the benefits of such operations, and there were only observations of surgeons that patients died without surgery). In the event of the development of threatening complications, the placebo should be discontinued immediately. If the patient stops taking the prescribed drug at any time, then he leaves the study.

For each patient, a report is filled out in the form of a separate card. CRF(case report form), including the original and 2 copies, one of which remains in the healthcare facility and is kept for 15 years.

Each investigator must provide detailed information about himself and must immediately inform the contracting authority of any identified serious adverse events. Some studies have been stopped early when investigators have received convincing evidence of adverse treatment outcomes (for example, a significant increase in mortality in the experimental group). But it also happens that clinical trials are suspended early if a huge advantage of a new drug or treatment is revealed.

Endpoints

To evaluate the results of the study, you need to select certain parameters that will be evaluated. The parameters are sorted in descending order of importance (primary, secondary, and tertiary endpoints).

Primary ("solid") endpoints are parameters associated with the life of patients and the development of life-threatening complications. The body as a whole is evaluated. Examples:

• overall mortality,
• the incidence of fatal myocardial infarction, stroke, ventricular fibrillation, etc.

Secondary and tertiary points are also called " soft" and " surrogate».

Secondary endpoints reflect the state of one or two body systems:

• improvement in quality of life due to relief of symptoms of the disease (for example, a decrease in the frequency of angina attacks),
• frequency of non-fatal (non-fatal) myocardial infarction,
• reduction in the incidence of non-lethal diseases (for example, paroxysm of atrial fibrillation).

Tertiary endpoints reflect changes in individual parameters, such as cholesterol or blood pressure.

When evaluating a new drug, one should always rely primarily on "solid" (primary) endpoints. Estimating only "soft" points can lead to serious errors. Perhaps that is why the points are called surrogate? Examples:

• cardiac glycosides in chronic heart failure, they increase the strength of myocardial contractions (tertiary point), reduce the frequency of hospitalizations and improve quality of life (secondary points), but do not lead to a decrease in overall mortality (primary point) due to an increased incidence of fatal arrhythmias (also primary point);
• with AIDS the administration of certain drugs that increase the content of T-helpers (tertiary endpoint) did not lead to a decrease in mortality (primary endpoint). For information: T-helpers are a type of lymphocytes that are affected by HIV.

Mega Research

The more high-quality studies conducted, the more reliable the results.

Mega Research(from mega- huge) - this is a study of new drugs for more than 10 thousand patients. In small groups of patients, the results are not so reliable, because in small groups:

• it is difficult to distinguish a positive result from treatment from spontaneous remissions of the disease,
• it is difficult to achieve homogeneity of groups,
• it is difficult to detect small positive changes in treatment and further prognosis,
• difficult to detect rare side effects.

Sometimes the statistically significant data of a mega-study on the benefits of a new drug are due to the presence among a large number of patients of a small group of patients who are highly sensitive to treatment. The rest of the new drug does not bring much benefit. Such patients who are highly sensitive to treatment should be identified. the new drug will bring maximum benefit only to them.

Schematic of the Heterogeneous Study Model

Meta-analysis

Meta-analysis(gr. meta- through) - combining the results of several controlled studies on the same topic. As the number of trials analyzed increases, it is possible to discover new positive and negative effects of treatment not seen in individual studies. Meta-analyses (meta-reviews) are by far the most important and valuable, because researchers analyze the quality of many clinical studies on a given topic, reject some for various reasons, and draw conclusions on the rest.

As you should know by now, when reading the results of any study, it is important to evaluate the primary endpoints first. For example, two meta-analyses found a positive antiarrhythmic effect lidocaine in myocardial infarction, and one meta-analysis was negative. What to believe? Recommend lidocaine for everyone with myocardial infarction? No, because the first two meta-analyses were on the effect of lidocaine on arrhythmias (i.e. secondary endpoints), and the third on the effect of lidocaine on myocardial infarction survival (primary endpoint). Thus, lidocaine successfully suppressed arrhythmias, but at the same time increased the mortality of patients.

Disadvantages of meta-analyses

Meta-analyses do not replace mega-studies and in some cases may even contradict them. Meta-analyses may be unconvincing in the following cases:

1. if a meta-analysis gives a generalized conclusion, although heterogeneous groups of patients participated in the studies. Or treatment began at different times and with different doses of drugs;
2. if the effectiveness of treatment is compared in some groups with placebo, and in others - with a known effective comparator, but the conclusion is general. Or the nature of concomitant therapy is not taken into account;
3. in cases of poor-quality randomization (the division into groups was not carried out randomly enough).

The results of meta-analyses help the doctor to choose the treatment, but they cannot be universal (for all occasions) and cannot replace the clinical experience of the doctor.

Levels of Evidence

In order to distinguish how strongly one can trust recommendations, gradations(A, B, C) and levels of evidence(1, 2, 3, 4, 5). I was going to give this classification here, but on closer examination I found out that all the classifications I had differed in details, since they were accepted by different organizations. For this reason, I'll just give one of the examples:

This is an example of the classification of levels of evidence and grades of recommendations

In order decreasing confidence The different types of studies are listed in the following order (source: Swedish Board for Health Evaluation Methodology):

• randomized controlled trial (i.e. having an experimental and control group with randomization),
• non-randomized controlled study with simultaneous control,
• non-randomized controlled trial with historical control,
• case-control study,
• crossover controlled study, cross-sectional study,
• observational results (open non-randomized study without group),
• description of individual cases.

How to analyze research results

All results obtained in a clinical study are processed using methods of mathematical statistics. The formulas and principles of calculations are quite complex, a practical doctor does not need to know them for sure, but in a medical university at the medical faculty they are introduced to them in two classes in physics in the 1st year and used in social hygiene (health care organizations) in the 6th year. Organizers of clinical trials carry out all calculations independently using statistical software packages.

1) Statistical validity. In medicine, any value is considered statistically significant if it is determined with a probability of 95% or more. This allows you to exclude accidental influences on the final result.

If the probability turned out to be less than 95%, then the number of analyzed cases should be increased. If an increase in the sample does not help, then it must be admitted that it is difficult to achieve a reliable result in this case.

2) Error Probability. Parameter denoted by a Latin letter p(p-value).

p- the probability of error in obtaining a reliable result. It is counted in fractions of a unit. Multiply by 100 to convert to a percentage. In clinical trial reports, there are three commonly used values: p:

• p > 0.05 - NOT statically significant (that is, the error probability is greater than 5%),
• p< 0.05 - является статистически значимым (вероятность ошибки 5% и меньше),
• p< 0.01 - высокая статистическая значимость (вероятность ошибки не выше 1%).

Now you are able to understand most of the findings in the publications of scientific medical journals. Practice:

A multicenter, randomized, prospective, open-label study with blinded endpoint evaluation was performed. ... A significant decrease in the insulin sensitivity index after 16 weeks of treatment compared with baseline values ​​was obtained both in the moxonidine group (p = 0.02) and in the metformin group (p = 0.03). There were no significant differences in this indicator between the studied groups (p = 0.92).