The importance of pharmacokinetic and pharmacodynamic drug interactions for practical pharmacotherapy
The drugs with a similar mechanism of action have the same character pharmacodynamic interaction and the different nature of the pharmacokinetic interaction. This is due to the difference of Performance drugs, the degree of ionization, polarity, lipophilicity, the ability to bind to blood proteins, and other ways of elimination., which affects the nature and intensity of their cooperation.
Not infrequently between the two medicinal substances simultaneously developing several types of interaction. If the effects of these interactions are opposite, the end result does not have an external display and practical value. Opposite, if they change the function of the body in one direction, the final effect should be taken into account in medical practice. For Example, phenylbutazone enhances hypoglycemic effect of tolbutamide, because it releases from the bond to plasma proteins, slows the biotransformation and excretion of the drug in the urine. As a result, the concentration of free tolbutamide in the blood, which can cause hypoglycemic coma.
If drugs have little breadth of therapeutic action (hypoglycemic sulfonureidy, antykoahulyantы indirect actions, cardiac glycosides, adrenomimetiki, antiarrhythmic and anti-epileptics), their interaction can be very dangerous. If necessary, the use of such drugs patients should be closely monitored, and the development of complications, arising from the interaction of drugs, should abandon the combination therapy.
Nevertheless, research data indicate, that the results of the interaction of drugs often used in clinical pharmacy to optimize drug therapy.
Currently, only the mutual influence of some representatives of various pharmacological groups of drugs, so-called prototypes. For Example, phenobarbital - in a series of derivatives of barbituric acid, Imipramine - group of tricyclic antidepressants and t. d. Until, It is at the disposal of experts (doctor, pharmacist) no specific data on the interaction of all the drugs, in clinical practice and dispensing professionals should be guided by the interaction of the alleged representatives of the entire group, had based prototype.
The practical interest of specialists in pharmacokinetics caused by the hope, that this direction will create the objective foundations of an effective and safe drug therapy through the transition from empirical approaches to scientifically based methods of drug treatment. Knowledge of the pharmacokinetic characteristics of drugs, consideration of possible interactions between drugs and their metabolites, the presence of comorbidities, establishing the relationship between the concentrations of drugs in biological liquids - all to create a science-based framework to optimize the treatment of patients.
Also between the drug sometimes occur dangerous interactions, that can lead to death.
