Polypharmacy in the elderly and medical interaction risks

Abstract

Medical comorbidity is frequent in the geriatric population. It is common for the elderly to be receiving seven o eight prescription drugs daily, and is higher among hospitalized patients. Significant changes associated with normal ageing and concomitant medical illness affect the pharmacokinetic and pharmacodinamic of psychotropic drugs. Substances distribution is affected by binding to plasma proteines and displacemente when they are strongly bound. Hepatic drug metabolism decreases with age resulting in a changed half life. The interactions between drugs are higher when the same group of isoenzimes of the cytochrome P450 metabolise many substances, accelerating or retarding its effects, and altering plasma concentration. Psychopharmacological treatment of the elderly implies peculiarities that must be taken into account because they are more sensible to the secondary effects. The most relevant interactions of psychotropic groups are studied.