The clinical application of tricyclic antidepressant pharmacokinetics and plasma levels

The authors present a clinical approach for predicting and using plasma concentrations of tricyclic antidepressants in the treatment of depressed patients. They review the pharmacokinetics of this group of drugs and their side effects and toxicity. There is a suggested therapeutic range for plasma concentrations of imipramine, amitriptyline, and nortriptyline; more definitive studies are needed to determine the necessary plasma levels for achieving clinical response with the other tricyclic antidepressants (desmethylimipramine, protriptyline, doxepin, clomipramine, impiramine N-oxide, and butriptyline). A more thorough knowledge of the clinical pharmacokinetics of tricyclic antidepressants should lead to more rational use of these drugs, with a higher response rate and fewer adverse reactions.