Priapism induced by boceprevir-CYP3A4 inhibition and α-adrenergic blockade: case report.

A 44-year-old white man presented to the emergency department with a 3-day history of priapism requiring a surgically performed distal penile shunt. A drug-drug interaction is the suspected cause whereby CYP3A4 inhibition by boceprevir led to increased exposures of doxazosin, tamsulosin, and/or quetiapine, resulting in additional α-adrenergic blockade.