trazodone
n. a chemically unique antidepressant that was introduced as a safer alternative to the tricyclic agents. Initially marketed in an immediate-release formulation, it was of limited use as an antidepressant due to its pronounced sedative effects and its association with prolonged, painful, and unwanted erections (priapism) in a very small number of men who took the drug. Its mechanism of antidepressant action is unclear; it is not a potent inhibitor of either serotonin or norepinephrine reuptake, and it is an antagonist at the 5-HT2 serotonin receptor. Nonetheless, trazodone is commonly used in low doses for bedtime sedation or in controlling agitation and hostility in geriatric patients (U.S. trade name: Desyrel). Additionally, in 2010, the U.S. Food and Drug Administration approved trazodone in an extended-release formulation for treatment of depression (U.S. trade name: Oleptro).