Plasma trazodone concentrations in elderly depressed inpatients: cardiac effects and short-term efficacy.

Twenty-three depressed patients with an average age of 78.86 were treated with trazodone in dosages averaging 354.3 mg/day. Despite pretreatment cardiac conduction delay in 30%, no electrocardiographic abnormalities were produced or exaggerated during the study. Plasma steady state levels averaged 1,474.4 ng/ml and significantly correlated with dosage at r = 0.415. In a subgroup of 13 patients, six who sustained good short-term response to trazodone had lower mean steady state plasma levels than seven who did not, suggesting that plasma levels about 1,500 ng/ml may not be therapeutic in the short run.