Sildenafil for Treatment of Priapism in Men With Sickle Cell Anemia

Study Overview
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Brief Summary
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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
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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.

Official Title
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Sildenafil for Treatment of Priapism in Men With Sickle Cell Anemia

Conditions
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Sickle Cell Disease, Priapism

Intervention / Treatment
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* Drug: sildenafil
* Other: placebo


Participation Criteria
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Eligibility Criteria
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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)

Ages Eligible for Study
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Minimum Age: 14 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: sildenafil<br>Participants assigned to this arm were given sildenafil 50 mg tablet daily for 16 weeks. | Drug: sildenafil<br>* sildenafil 50 mg tablet daily for first 8 weeks (phase 1), and then sildenafil 50 mg tablet daily for final 8 weeks (phase 2)<br>* Other names: Viagra;|
| Placebo Comparator: placebo<br>Participants assigned to this arm were given a placebo pill for the first 8 weeks, and then Sildenafil 50 mg for weeks 9-16. | Other: placebo<br>* placebo 50 mg tablets daily for first 8 weeks (phase 1), and then sildenafil 50mg tablet daily for final 8 weeks (phase 2)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Greater Than or Equal to a 50% Reduction in Priapic Episodes | 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. | change between baseline and 8 weeks post intervention | 
| Greater Than or Equal to a 50% Reduction in Priapic Episodes | 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. | change between 8 weeks post intervention and 16 weeks post intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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priapism, sickle cell disease, sildenafil, phosphodiesterase type 5 inhibitor