Chlorpromazine-tadalafil interaction leading to refractory ischemic priapism and penile prosthesis implantation: a case report

Background Priapism represents a rare urological emergency characterized by persistent penile erection unrelated to sexual stimulation. Although chlorpromazine-induced priapism has been documented, the synergistic interaction with phosphodiesterase type 5 inhibitors resulting in refractory cases necessitating penile prosthesis implantation constitutes a novel clinical scenario requiring comprehensive documentation. Case presentation We report a 56-year-old male who developed refractory ischemic priapism following self-administration of oral chlorpromazine for hiccups, taken 24 h after tadalafil 20 mg for erectile dysfunction. The patient had previously experienced a transient priapism episode 10 years earlier following isolated chlorpromazine use, establishing chlorpromazine as the primary etiological agent. Despite comprehensive management including corporal aspiration, intracavernosal sympathomimetic injection, and distal T-shunt creation, the patient developed recurrent priapism requiring penile prosthesis implantation. Conclusions This case demonstrates compelling evidence of a dangerous chlorpromazine-tadalafil interaction resulting in treatment-refractory priapism. The synergistic pharmacological effects of alpha-adrenergic blockade and phosphodiesterase type 5 inhibition created a severe clinical presentation necessitating immediate penile prosthesis implantation. Healthcare practitioners must recognize this potentially devastating drug interaction and implement preventive measures through comprehensive medication reconciliation and patient counseling.