Priapism, Sickle Cell Disease
Conditions
Keywords
priapism, sickle cell disease, sildenafil, phosphodiesterase type 5 inhibitor
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.
Interventions
DRUGsildenafil
sildenafil 50 mg tablet daily for first 8 weeks (phase 1), and then sildenafil 50 mg tablet daily for final 8 weeks (phase 2)
OTHERplacebo
placebo 50 mg tablets daily for first 8 weeks (phase 1), and then sildenafil 50mg tablet daily for final 8 weeks (phase 2)
Sponsors
National Institutes of Health (NIH)
Johns Hopkins University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
MALE
Age
14 Years to 45 Years
Healthy volunteers
No
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)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Greater Than or Equal to a 50% Reduction in Priapic Episodes | change between baseline and 8 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. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Sildenafil Participants assigned to this arm were given sildenafil 50 mg tablet daily for 16 weeks | 6 |
| Placebo Then Sildenafil Participants assigned to this arm were given a placebo pill for the first 8 weeks, and then sildenafil 50 mg for weeks 9-16. | 7 |
| Total | 13 |
Baseline characteristics
| Characteristic | Sildenafil | Placebo Then Sildenafil | Total |
|---|---|---|---|
| Age, Continuous | 21.7 years STANDARD_DEVIATION 5.3 | 23.0 years STANDARD_DEVIATION 8.7 | 22.5 years STANDARD_DEVIATION 7 |
| Region of Enrollment United States | 6 participants | 7 participants | 13 participants |
| Sex: Female, Male Female | 0 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Male | 6 Participants | 7 Participants | 13 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 5 / 6 | 5 / 7 | 2 / 4 | 0 / 4 |
| serious Total, serious adverse events | 3 / 6 | 1 / 7 | 1 / 4 | 0 / 4 |
Outcome results
Primary
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.
Time frame: change between baseline and 8 weeks post intervention
Population: Intention to treat analysis.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Sildenafil | Greater Than or Equal to a 50% Reduction in Priapic Episodes | 3 Number of participants |
| Placebo Then Sildenafil | Greater Than or Equal to a 50% Reduction in Priapic Episodes | 3 Number of participants |
Comparison: Null hypothesis: there would be no difference in the number of participants who experienced at least a 50% reduction in the frequency of priapic episodes between baseline and 8 weeks post intervention, between the sildenafil and placebo groupsp-value: 1Fisher Exact
Primary
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.
Time frame: change between 8 weeks post intervention and 16 weeks post intervention
Population: 3 participants from the Phase 1 Sildenafil group were lost to follow up during the second phase; 2 individuals from the Phase 1 Placebo then sildenafil group were lost to follow up during the second phase.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Sildenafil | Greater Than or Equal to a 50% Reduction in Priapic Episodes | 2 Number of participants |
| Placebo Then Sildenafil | Greater Than or Equal to a 50% Reduction in Priapic Episodes | 3 Number of participants |
p-value: 0.55Fisher Exact