[Evaluation of therapeutic efficacy and pharmacokinetics of controlled release of trazodone in patients with major depressive disorder].

In the present study, the antidepressant efficacy of a controlled-release (CR) formulation of trazodone was evaluated in 18 depressed patients treated with 150 mg (no. = 10) or 75 mg (no. = 8) nocte doses of the drug for 7 weeks, according to an open design. Drug plasma levels were evaluated on days 7, 14, 28 and 35 of treatment. Moreover, at the end of treatment, the plasma concentration-time curve of the CR trazodone was assessed. CR trazodone was effective in improving depressive and anxious symptomatology as well as in ameliorating the quality of sleep in 13 patients with a low incidence of side effects. Nonresponder subjects had morning plasma levels of trazodone below the value of 650 ng/ml. The pharmacokinetic profile of CR trazodone, observed after 35 days of treatment, may account for both the low occurrence of untoward side effects and the therapeutic efficacy of the single dose at nighttime.