Trazodone (Desyrel, Mead-Johnson Pharmaceutical Division).
Trazodone is the first triazolopyridine derivative to be used clinically for the treatment of depression. It has been shown to be equal in efficacy to the tricyclic antidepressants imipramine, desipramine, and amitriptyline in the treatment of major depressive episodes. Researchers have indicated that trazodone exceeds other antidepressants in relieving anxiety, but further study is needed to confirm this effect. Trazodone has been used successfully to relieve depression in schizophrenic patients without worsening their psychotic symptoms. Trazodone blocks serotonin reuptake into presynaptic neurons with little effect on norepinephrine or dopamine. It is rapidly absorbed orally and reaches peak serum levels within two hours. Trazodone is excreted primarily as metabolites by the kidneys and possesses a biphasic elimination half-life of 4.4 hours for the first 10 hours and 7.5 hours for the next 24 hours. Trazodone 200 mg is equal to imipramine 100 mg, and the therapeutic dosage range is 200-600 mg/d. Side effects are infrequent with trazodone; its anticholinergic activity is minimal. Trazodone appears to produce less cardiovascular toxicity than tricyclic antidepressants. To date, reports of fatal overdoses are rare. Trazodone equals available antidepressant drugs in clinical efficacy, and, because it has fewer cardiovascular and anticholinergic side effects, it should prove beneficial in the treatment of depression.