April 19, 2002
By Jill Stein
Special to DG News
New data suggest that the efficacy and tolerability of Viagra (sildenafil) in men with erectile dysfunction and multiple sclerosis is sustained over periods ranging from 24 to 48 weeks.
The results were announced here yesterday at the 54th Annual Meeting of the American Academy of Neurology (AAN) by Dr. James R. Miller, with the New York Neurological Institute, in New York City.
While sildenafil has previously been shown to improve erectile dysfunction (ED) in men with multiple sclerosis (MS) in a placebo-controlled trial, the present study reviews the efficacy and safety of the drug during the 24- to 48-week open-label extension phase of this trial. A total of 100 patients were randomized to sildenafil 50 mg and 106 to placebo in the first phase of the study. Of these, 180 patients completed the open-label extension phase.
The double-blind end point efficacy assessment served as baseline for the open-label extension phase. At the final open-label extension visit, a limited assessment of efficacy was made based on responses to three questions on the Global Efficacy Assessment Questionnaire (GEQ).
GEQ1: "Compared to having no treatment at all for your erection problem, had the medication you have been taking over the past four weeks improved your erections?"
GEQ2: "If yes, has the improvement in your erections allowed you to engage in satisfactory sexual activity?"
GEQ3: "When you took a dose of the study drug and had sexual stimulation, how often did you get an erection that allowed you to engage in satisfactory sexual activity?"
At the end of the open-label extension phase, the efficacy of sildenafil was sustained, with 95 percent of men reporting improved erections. Of those patients, 95 percent also reported improved sexual activity. Patients who received placebo during the double-blind phase showed a nearly fourfold increase in improved erections at the end of the open-label extension (97 percent versus 26 percent).
Men from both the double-blind placebo group (96 percent vs. 73 percent) and the sildenafil groups reported improvement in successful sexual activity (94 percent vs. 89 percent). Since only patients who responded "yes" to GEQ1 were included, however, fewer patients from the double-blind placebo group (n=26) than from the sildenafil group (n=81) answered the GEQ2.
The frequency of erections (GEQ3) more than doubled in the double-blind placebo patients (mean score 4.35 vs. 1.98), and was similar to the frequency observed in men who received double-blind sildenafil (mean score 4.26).
The study found no increase in the incidence of adverse events, or any specific type of adverse event, emergent with the extended use of sildenafil.
Sexual dysfunction, and especially ED, is a common problem for men with MS. Several reports have shown the incidence of ED in men with MS to be 50 percent to 75 percent.
The trial was supported by Pfizer, Inc.
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