Tadalafil for Treatment of Priapism in Men With Sickle Cell Anemia

This study will investigate phosphodiesterase 5 (PDE 5) inhibitor therapy as a potential treatment for recurrent ischemic priapism. Enrolled participants will be randomized to receive oral 10 mg tadalafil tablets 3 times a week or receive matching placebo. Patients will be instructed to use the medication in the morning a few hours after awakening from night time sleep, and they will be instructed against engaging in any form of sexual activity or excitement within 8 hours of dosing. Treatment duration will be 2 months for each participant. After the 2 month period, participants on tadalafil and placebo will be offered tadalafil (same dosing regimen) for an additional 2 months. The study duration will be 4 months. Tests and procedures will include: consent; medical history; physical examination; clinical laboratory tests; completion of questionnaires; and medication dispensation.