Priapism from quetiapine overdose: first report and proposal of mechanism.

We report a case of priapism occurring after an overdose of the newly approved atypical antipsychotic quetiapine. A review of its previously published receptor-binding studies suggests that alpha-adrenergic blockade may be the responsible mechanism. To our knowledge, this is the first report of priapism associated with quetiapine, and we recommend the inclusion of priapism in its list of potential adverse effects in cases of overdose.