Priapism following a switch from oral to injectable chlorpromazine: a rare occurrence

Abstract

Chlorpromazine is a common antipsychotic medication. Several cases of priapism emanating from drugs administrations including antipsychotic drugs have been reported in the past, but priapism as a result of a switch from oral to injectable chlorpromazine is quite rare. We report a 31 year old male patient following a switch from oral to intramuscular chlorpromazine for the control of sudden aggressive schizophrenic episode. He had Al-ghorab shunt procedure after an initial unsuccessful conservative management. The outcome of the procedure was satisfactory, he achieved erection and performs coitus thereafter. Priapism can occur due to persistent antagonistic effect of antipsychotics on alpha adrenergic receptors, this can be precipitated by increase in dosage, poly-pharmacy or switching the route of administrations as observed in the index case. Awareness of patients about the adverse effects of these drugs is important. Drugs with little or no alpha adrenergic effects should be prioritized in other to avoid priapism. Unnecessary switch of route of administration should be avoided.

Keywords: Antipsychotics, Chlorpromazine, Erection, Priapism, Psychotropics