From Big Medical Encyclopedia

PLACEBO (Latin placebo future time, from armor. placere to be pleasant) — the term used generally for designation of so-called «imaginary drugs» i.e. the drugs representing substances, indifferent for an organism, or substances with very weak pharmakol, activity. The item is used by hl. obr. at comparative a wedge, tests new pharmakol, drugs, and also in therapeutic practice.

At a wedge, P.'s tests apply to an exception of psychotherapeutic (nonspecific) effect of the tested drugs. At this P. the maximum looking alike by the tested drug in a form, color, taste and a smell is given. In therapeutic practice of P. apply when at the disposal of the doctor there are no effective remedies, or in addition to active therapy. Sometimes the doctor uses P. if considers inexpedient appointment or continuation of use of active drug, and the patient insists on its use.

The item can give both positive, and negative effect.

The positive effect can be shown by objective and (or) subjective improvement of health of the patient and weakening of symptomatology of a disease. The negative effect of P. which is designated the term «notsebo» is characterized by strengthening of the existing symptoms and (or) emergence of new symptomatology. Most often notsebo it is shown by slackness, drowsiness, a headache, sleeplessness, dizziness, went. - kish. frustration. Usually manifestations notsebo happen poorly expressed.

The item causes changes not in all people — only apprx. 30% reacts to P.'s reception by change of mood, intellectual and physical capacities. At various diseases the positive effect of placebo is shown more often. Consider that about 40% of patients react to P.'s reception on average. P.'s action at some mental disorders which are followed by concern, a depression, etc. is especially expressed.

At P.'s use functions of various bodies and systems can change. In some cases P. improves a condition of patients at stenocardia, a pseudorheumatism, pain syndromes, a headache, cough, round ulcers, an idiopathic hypertensia, etc.

P.'s effects, as a rule, appear and stop quickly. Origins and physiological bases of action of P. are studied a little. The large role in P.'s effect is played by such factors as identity of the patient, the identity of the doctor, the nature of their relationship and feature of the environment. The sensitive, expecting the help from the doctor and believing in him patients react to P. Vesm's reception stronger the situation in which there is a patient receiving P. and the relation to it of medical staff and other patients is important. A part in P.'s efficiency is played by outward of its packaging. So, for example, tablets and capsules of red color are much more active (especially in pediatric practice), than tablets and capsules of gray color.

At P.'s use in process the wedge, tests of new medicinal substances very important is the solution of the ethical problems connected using P., especially at its use in double «blind» researches when the attending physician does not know what patients accept P. and what — active drug. The philosophy at the solution of a question of a possibility of appointment of P. to each patient is respect for its interests. The item can be appointed only if temporary lack of active treatment does not do harm to the patient participating in a research. Inadmissibly, e.g., P.'s use instead of active drugs at hypertensive crises, an acute heart failure and other states demanding effective acute management.

At a wedge, tests it is necessary to aim to compare the studied drug not to P., and to «standard» active drug.

Placebo effect is characteristic not only for true P.'s action, but in a varying degree takes place during the performing active medicinal therapy. At the same time sometimes improvement of a condition of the patient can be connected not only with specific effect of medicine, but also with its nonspecific placebo effect. In this regard at prescription of medicines it is always necessary to consider and use both their specific pharmakodinami-chesky action, and placebo effects.

Bibliography: L. A. butchers and V. I Blizzard. The differentiated treatment hronicheskokhg coronary heart disease, page 53, M., 1974; And with h a m Ь and - 111 t J. Page of et D u b about i s - In r i 11 e t A. M of L'effect placebo, Vie med., p. 837, 1980; Benson H. E p s t e i n M. D. The placebo effect, J. Amer. med. Ass., v. 232, p. 1225, 1975, bibliogr.

B. K. Lepakhin.