Nortriptyline plasma levels and therapeutic response

Abstract

Eighteen depressed outpatients were treatedfor 6 wk with a mean daily dose of 121 mg of nortriptyline. The mean plasma level was 138 ng/ml during treatment. Therapeutic response was monitored by the Zung Self‐Rating Depression Scale and the Hamilton Depression Scale administrered by two psychiatrists blind to the tricyclic used, dose, and plasma levels. Eight patients recovered (Hamilton ≧ 6) by the fourth week and 12 by the sixth week. During the steady‐state (wk 4 to 6) there was a positive correlation between the weekly Hamilton scores and the weekly nortriptyline levels (p < 0.01). The 9 patients with mean plasma levels between 50 and 139 ng/ml had a better therapeutic response after 6 wk measured by percent recovered (p < 0.005), Zung score (p < 0.05), and Hamilton score (p < 0.025) than the 9 patients with mean plasma levels between 140 and 260 nglml.