Therapeutic drug management antidepressants

Therapeutic drug management (TDM) of most antidepressants is not widely available or widely utilized, for any clinical indication. The primary benefits of TDM in the management of antidepressant therapy could include assessment of patient compliance, detection of drug-drug interactions or altered pharmacokinetics, and evaluating the concentration relationship of individual patient response and/or thresholds for dose-related side effects. Of all the classes of antidepressant drugs, TDM of TCAs is most common. 

Plasma levels of some of the tricyclic antidepressants can be measured by clinical laboratories. Therapeutic concentrations are usually less than 0.3 mg/L (300 ng/mL). Total concentrations of parent drug plus metabolite of 1 mg/L (1000 ng/mL) or greater are usually associated with serious poisoning. Generally, plasma levels are not used in emergency management because the QRS interval and clinical manifestations of overdose are reliable and more readily available indicators of toxicity. 

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