General principles of drug therapy in psychiatry

Abstract

Abstract The successful use of psychotropic drugs demands an understanding of their pharmaceutical, pharmacokinetic, and pharmacodynamic properties. ♦ Pharmaceutical properties: Pharmaceutical formulations can be manipulated to produce different durations of action, for example the use of oily emulsions of antipsychotic drugs in depot formulations. ♦ Pharmacokinetic properties: Pharmacokinetics is the mathe-matical description of the disposition of drugs in the body by absorption, distribution (to plasma proteins and tissues), and elimination (usually by hepatic metabolism and renal excretion). Differences in drug disposition determine differences in dosage regimens and are important for drug interactions. ♦ Pharmacodynamic properties: Pharmacodynamics is the study of the pharmacological actions of drugs and how actions at the molecular level are translated, via actions at cellular, tissue, and organ levels, into therapeutic or adverse effects. The known pharmacological actions of psychotropic drugs are not necessarily the actions that produce their therapeutic or adverse effects.