Trazodone dosing regimen: experience with single daily administration.

Efficacy being constant, antidepressant choice is dictated by side effect profile, patient acceptance, and safety. Trazodone has been shown to be safe in overdose, and the side effect profile is mild, with sedation the most common side effect. Sleep electroencephalogram and clinical studies have shown trazodone effective in improving sleep in normal subjects, insomniac patients, and patients with major depression. Tolerance and rapid eye movement rebound on discontinuation do not occur. The 3- to 9-hour half-life of trazodone and its pharmacokinetics favors a dose weighted at bedtime. Studies comparing multiple daytime dosing to single dosing at bedtime have shown equal efficacy in relieving depression. At treatment onset, a single nighttime dose is more productive of sleep with less daytime drowsiness. These differences between single nighttime dosing and multiple daily dosing disappear with continued administration. Geriatric patients respond similarly. Trazodone is best dosed at 150 mg given predominantly (but not necessarily all) at bedtime and increased as needed to 200 to 300 mg for full antidepressant efficacy.