Topical Agents
Topical agents to treat erectile dysfunction are applied to the penis or perineal regions and have included hormone-derived medications, as well as vasodilators.
| Author Year; Country Score Research Design Total Sample Size |
Methods | Outcome |
|---|---|---|
| Kim et al. 1995; USA Prospective controlled trial Level 2 N=20 |
Population: 13 men with SCI, 7 non-SCI Age: range 19-73 yrs, Duration of erectile dysfunction: range 0.6-27 yrs. Treatment: Papaverine gel or placebo gel, dose range: 133-500mg. Outcome Measures: Safety and efficacyof topical papaverine gel. |
For SCI patients (n=12) 1. 3 patients with papaverine gel had full erections, but full erections also occurred with placebo gel. |
| Kim et al.1995; USA Pre-post Level 4 N=10 |
Population: Men with SCI (n=9), 1 arterial insufficiency; Age: mean 33 yrs, range 19- 50; Injury level: cervical (n=4), thoracic (n=5) Treatment: Topical prostaglandin E1 to penis, scrotum, and perineum. Outcome measures: Color flow Doppler Ultrasound for cavernous artery diameter and peak systolic flow velocity, vital signs: systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), clinical erection, adverse events. |
1. Mean cavernous artery diameter increased from 0.09 to 0.11 cm. 2. Mean peak systolic flow velocity increased from 15.4 to 22.8 cm/sec. 3. Clinical erections were observed in 2 men. 4. Vital signs were unaffected by PGE1. 5. No adverse events. |
| Chancellor et al. 1994; USA Post-test Level 4 N=18 |
Population: 18 men with SCI, Age: range 19-65 yrs, Level of injury: C7-L3 (15 thoracic). Treatment: Minoxidil spray, papaverine injection, or vacuum constriction device (VCD). Outcome Measures: Erectile response. |
1. Papaverine injections increased median rigidity 77% (range 30-100%). Rigidity was significantly less with minoxidil. 2. Vacuum constriction device changed rigidity a median of 57% (range 30- 80%). 3. No difference between vacuum constriction device and papaverine. 4. Patient subjective rating scale was significantly lower for minoxidil than vacuum constriction device or papaverine. 5. Physicians’ subjective ratings were significantly lower for minoxidil than other treatments. |
| Beretta et al. 1993; Italy Post-test Level 4 N=15 |
Population: 15 men, age range: 20-38 yrs, Level: T2-L5. Treatment: Prostaglandin E1 and 2% Minoxidil solution. Outcome Measures: Erectile response. |
4 patients had complete responses, 5 had partial, 6 had no response. 2. 9 patients with complete/partial response continued to use minoxidil at home for 1 month. 3. 26.6% obtained an erectile response sufficient for vaginal penetration. |
| Sonksen et al. 1992; Denmark Post-test Level 4 N=17 |
Population: 17 men, age range: 19-51 yrs, level: C2-L4, 13 complete, 4 incomplete. Treatment: Transiderm-Nitro plaster (10mg/24hrs), which contains 50mg glyceryl trinitrate. Outcome Measures: Erectile response. |
1. 5 patients had complete responses (full rigidity), 7 had partial responses (some rigidity and/or increase in penile circumference), and 5 had no response (no noticeable erection). 2. Erection duration (complete response): 20-45 min. 3. 5 (29%) had erections sufficient for vaginal penetration. |
Discussion
There are no RCT studies in this area. Topical agents that cause vasodilation, such as minoxidil, PGE1, papaverine and nitroglycerine, are generally safe yet found to be effective only in a minority of patients (providing an erection sufficient for vaginal penetration in 22-29%), most likely due to inadequate absorption through the tunica albuginia. Kim & McVary (1995), although showing a significant increase in mean cavernous artery diameter and mean peak systolic flow velocity with topical application of PGE1, reported a clinically useful erection in only 2 out of 9 subjects. One study found topical minoxidil spray to be significantly less effective than comparative treatments with papaverine ICI or a vacuum constriction device. Use of topical agents to treat ED seem to have little if any role to play in the SCI population, particularly in view of the efficacy and reliability of PDE5i and ICI.
Conclusion
There is level 2 evidence (from 1 non-randomized controlled trial: Kim and McVary 1995) that shows that the use of topical agents is not effective as treatment for erectile dysfunction in men with SCI.
