Occurrence of trazodone-induced delirium.

Trazodone, a triazolepyridine derivate, is both chemically and pharmacologically distinct from other serotonin reuptake inhibitors and possesses antidepressant, anxiolytic and hypnotic activity. We observed trazodone-induced delirium in three depressed patients who also suffered from preexisting organic cerebral lesions (two cases) or thyroideal dysfunction (one case). The appearance of hallucinations, psychomotoric agitation, and cognitive changes after initiation of trazodone therapy and their prompt cessation after drug discontinuation led to the impression that these were drug-induced phenomena. One possible hypothesis for the observed deliria is an oversensitivity to the effect of meta-chlorphenylpiperazine, which is a metabolite of trazodone with specific 5-HT agonistic properties.