Pharmacokinetics of psychotropic drugs: what can it tell us?

1. Knowledge of basic pharmacokinetic parameters may help the clinician to optimize drug treatment regimen. 2. For some psychotropic drugs (e.g. lithium and some antidepressants) a good correlation exists between plasma levels and therapeutic or toxic effects. 3. "Optimum" steady state levels can now be predicted from single dose blood level data of some drugs (lithium, nortriptyline, desipramine). 4. Altered pharmacokinetics in elderly and children have to be taken into consideration in treatment with psychotropic drugs. 5. With development of suitable drug assays, plasma level control of therapy is becoming a part of a good clinical practice.