Interaction of drugs in bioreceptors
The interaction of drugs with bioreceptors organism largely depends on their concentration, and local processes - Transport, biotransformations, binding of an indifferent, etc.. An example of such cooperation can serve as a reinforcement and extension of time analgesic effect of local anesthetic substances under the influence of a vasoconstrictor, to reduce the absorption and prevent decrease of concentration of anesthetic at the site of administration.
An example summation effects can serve as a combined use of substances and pharmacological groups close chemical structure, which react with the same type receptors. So, when applying asfena, which is composed of half-dose of drugs (acetylsalicylic acid 0,25 Mr. and phenacetin 0,15 g), It achieves the desired analgesic and antipyretic effect of the drug with a less irritating effect of acetylsalicylic acid and toxic effects of phenacetin. Strengthening effect of the drug is achieved through involvement in a large number of similar reactions receptors.
The antagonistic drug interactions allocate direct antagonism, Competitors and indirect, as well as a partial. Each of these types of interaction is different, depending on whether, Does the substance react, included in the combination, with the same or different receptors. An example of competitive interaction for communicating with the receptor can serve as the antagonism between atropine, блокирующим M-холинорецепторы, and acetylcholinesterase inhibitors, increases the concentration of acetylcholine.
The reaction can occur a change in the sensitivity of specific receptors by direct (eg, sensitization of the myocardium to adrenaline during ftorotanovogo or cyclopropane anesthesia) or indirectly (eg, Sensitization myocardial cardiac glycosides by reducing the content of potassium ions, caused by diuretics) effect of drugs on the target cell. Changes in intestinal microflora, caused by antimicrobial agents, It leads to disruption of the synthesis of vitamin K and, thereby, potentsyruet effect antykoahulyantov indirect actions.
