Stuttering priapism in a liver transplant patient with toxic levels of fk506.

This is the first report of stuttering priapism in a liver transplant patient with toxic levels of the immunosuppressive agent FK506. To date, stuttering priapism has only been reported in patients with sickle cell disease and is not currently listed in the toxicity profile of FK506 or cyclosporine, a drug with a similar mechanism of action. The erections resolved when the FK506 levels normalized. We review the possible mechanisms by which FK506 may have caused these erections.