Articles: PDF OnlyMonteleone Palmiero; Gnocchi, GiorgioClinical Neuropharmacology: 1990 - p S84-S89 Buy Abstract Summary: To investigate a possible relationship between plasma levels of trazodone and its clinical antidepressant effects, 11 elderly depressed patients underwent a 5-week treatment with 150 mg/day trazodone in three oral administrations. Clinical antidepressant response was assessed with two different clinical improvement criteria and plasma trazodone concentrations were determined by high-performance liquid chromatography. A significant correlation was found between steady-state plasma trazodone levels and its antidepressant efficacy, but not between plasma drug levels and the incidence of side effects. Moreover, the steady-state plasma trazodone concentration of 650 ng/ml was identified as threshold value for a greater occurrence of good antidepressant responses. Address corrspondence and reprint requests to Dr. P. Monteleone at Servizio di Salute Mentale della U.S.L. 41, regione Campania, via Fondo Cancello, 80145 Napoli, Italy. © Williams & Wilkins 1990. All Rights Reserved.