[Clinical pharmacokinetics of tricyclic antidepressants Part II. Drug therapy monitoring]

Large interindividual variation in steady-state TCA plasma concentrations, the presence of active metabolites, narrow therapeutic range and life-threatening results of TCA overdosage constitute indications for therapeutic drug monitoring. Conditions which must be fulfilled in order that serum concentration measurements may be taken into consideration in routine practice were discussed. The most important ones are: relationship between TCA concentration and antidepressant effect, the knowledge of therapeutic TCA range and availability of rapid and sensitive analytical method. Pharmacokinetic methods of TCA dosage individualization were also described. TCA serum concentration monitoring and dosage individualization of these drugs allows the clinician to optimize treatment of depression.