Trazodone--a comparison of single night-time and divided daily dosage regimens.

The antidepressant efficacy, influence on sleep variables and incidence of side-effects of trazodone (100-400 mg daily), given either as a single night-time dose or thrice daily, were compared in a double-blind, 4 week, parallel group, multicentre hospital study. Of 56 patients who entered the study, full data was available for 37, of whom 20 took the medication at night and the other 17 received divided doses during the day. The results showed equivalent therapeutic efficacy for the two dosage regimens and tolerance was good in both groups. For onset and also duration of sleep, significantly more patients in the single night-time group improved than worsened in response. Both groups of patients tended to report a more satisfying sleep and greater freshness on waking, although these latter effects were not statistically significant. For the group taking trazodone thrice daily, there was a trend for more complaints of side-effects, particularly dry mouth, headache and drowsiness which led to more of these patients requiring modification of dosage. Thus trazodone appears to have clinically useful sedative properties. It has relatively few side-effects and these are generally reduced by giving a single dose at night.