From Big Medical Encyclopedia

SYNERGISM OF MEDICINAL SUBSTANCES (Greek synergia assistance, partnership) — the result of action jointly the applied medicinal substances which is expressed in summation or potentiation of effect of separately taken substances. It is observed at simultaneous or consecutive (suktsessivny) use of medicinal substances. Page of l. is considered century as are additive and if the final effect is equal to the sum of effects of each of components of a combination of medicinal substances (summation of effects). When medicinal substances cause the joint effect surpassing the sum of effects of each substance separately the net result is estimated as the l potentiated by S. century (potentiation of effects).

At the heart of S. of l. century influence of one substance can lie on pharmacokinetics (see) and (or) pharmacodynamics (see) another. Page of l. century, based on pharmacokinetic interaction of drugs, can be result: accelerations of absorption (e.g., acceleration of absorption of alkaloids in went. - kish. a path at their combined use with antiacid means); delays of absorption (e.g., novocaine from hypodermic cellulose in the presence of adrenaline); replacement by one substance of other of communication with proteins of a blood plasma (e.g., glucocorticoids salicylates); increases in permeability of gisto-gematichesky barriers to one substance under the influence of another (e.g., aminazine increases permeability of a blood-brain barrier for Mannitolum); inhibition of the enzymes metabolizing other substance (e.g., prozerin slows down hydrolysis of Dithylinum, inhibiting cholinesterases); delays of allocation by kidneys of one substance by another (e.g., probenetsid and others organic to - you slow down excretion of penicillin and PASK).

Page of l. century, based on pharmakodinamichesky interaction, can be result of independent impact of substances on different functionally significant biosubstrates (enzymes, membrane or cytoplasmatic receptors, ionophores). So, a synergism of cardiotonic effect of adrenaline and caffeine is caused by accumulation in a myocardium of cyclic adenosinemonophosphate (tsAMF) that is caused by activation by adrenaline of adenylatecyclase and inhibition of phosphodiesterase under the influence of caffeine.

Page of l. can be also a consequence of impact of drugs on the same macromolecular substrates of cells century. Depending on coincidence or discrepancy of sites of a macromolecule, with to-rymi medicinal substances interact, the additive or potentiated synergism is observed respectively.

The potentiated synergism widely is used in a wedge, practice since allows to gain therapeutic effect at smaller doses of kombiniruyekhmy drugs in this connection the probability and degree of manifestation of side effects and complications decreases. However in some cases owing to S. of l.

century strengthening of undesirable effects at simultaneous or consecutive use of medicinal substances is possible (see. Side effects of pharmaceuticals ).

Bibliography: Komissarov I. V. Elements of the theory of receptors in molecular pharmacology, M., 1969; S with h e-I e r W. Grundlagen der allgemeinen Phar-makologie, Jena, 1980.

I. V. Komissarov.