BCEN CEN Practice Question

Intracavernosal injection therapy with vasoactive agents (e.g., alprostadil, papaverine, phentolamine, or Trimix) is the leading drug-related cause of ischemic priapism in adults. These agents directly relax cavernosal smooth muscle, and when detumescence mechanisms fail the resulting venous outflow obstruction produces a prolonged, painful erection characteristic of low-flow priapism. Oral phosphodiesterase-5 inhibitors can rarely cause priapism, but they account for far fewer cases. Perineal blunt trauma typically produces high-flow (non-ischemic) priapism via an arteriocavernosal fistula, and autonomic dysreflexia from acute spinal cord injury is an uncommon neurogenic trigger, not the predominant iatrogenic cause.