Sildenafil for Treatment of Priapism in Men With Sickle Cell Anemia

Phase 2

Completed

Brief Summary: This research is being done to evaluate if the phosphodiesterase type 5 (PDE5) inhibitor sildenafil has an effect on the frequency of recurrent priapism and the quality of life of males with sickle cell disease (SCD).

Detailed Description: 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.

Recruitment & Eligibility

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)

Arm && Interventions

Group	Intervention	Description
placebo	placebo	Participants assigned to this arm were given a placebo pill for the first 8 weeks, and then Sildenafil 50 mg for weeks 9-16.
sildenafil	sildenafil	Participants assigned to this arm were given sildenafil 50 mg tablet daily for 16 weeks.

Primary Outcome Measures

Name	Time	Method
Greater Than or Equal to a 50% Reduction in Priapic Episodes	change between 8 weeks post intervention and 16 weeks post intervention	A "Priapism sexual activity log" was administered to participants. In the log, participants were asked to quantify the number of priapic episodes they had experienced in the previous 2 weeks according to the following scale/tiers: 0 = no episodes, 1 = 1-2 episodes, 2 = 3-4 episodes, 3 = 5-8 episodes and 6 = greater than 20 episodes.

Secondary Outcome Measures