Sildenafil for Treatment of Priapism in Men With Sickle Cell Anemia

The proposed research is designed to investigate the utility of continuous, long-term PDE 5 inhibitor therapy as an intervention for recurrent ischemic priapism, a disorder of non-willful, excessive penile erection, in patients with SCD. Although precise prevalence figures are not available, priapism in SCD is highly prevalent and thought to afflict approximately 40% of males, based on available literature. Additionally, the disorder exacts devastating consequences, including erectile tissue necrosis, erectile dysfunction, and psychological distress. Management of this disorder remains challenging because the mechanisms underlying priapism are incompletely understood.

Inclusion criteria

• Ages 14 to 45, inclusive
• Episodes of prolonged penile erection in the absence of sexual interest or desire, with an average frequency of at least twice weekly, when averaged over the previous four weeks
• Able to provide informed consent or assent

Exclusion criteria

• Use of chronic nitrates or recreational use of nitrate containing products
• Use of a PDE5 (phosphodiesterase type 5)inhibitor within the previous two weeks
• Alcohol use exceeding two standard drinks daily
• Hypersensitivity to sildenafil
• Estimated glomerular filtration rate <50ml/min
• Known cirrhosis
• Retinitis pigmentosa
• Necessary use of a P450 3A4 inhibitor (a drug which can increase plasma levels of sildenafil when taken together)