Oral drug effectively improves premature ejaculation
Investigational agent increases ejaculatory latency time by 1.5 minutes over baseline
The serotonin transport inhibitor dapoxetine appeals to be a well-tolerated and effective agent for the treatment of premature ejaculation, according to the results of a phase II study presented at the International Society for Sexual and Impotence Research world congress.
Researchers say the drug, which is still investigational, may offer a safer, more tolerable altemative to the Dr. Hellstrom selective serotonin reuptake inhibitors (SSRIs) currently used to treat this common sexual condition.
The randomized, double-blind, placebo controlled triai enrolled 166 adult, heterosexual men with a baseline intravaginal ejaculatory latency time (lELT, as measured by a stopwatch held by the female partner) <2 minutes (mean time, 1.01 minutes). Subjects were randomized to initial treatment with dapoxetine, 60 mg or 100 mg taken 1 to 2 hours prior to anticipated sexual activity, or placebo. Patients were crossed over to both alternate treatments. Treatment periods lasted 2 weeks and were separated by a 72-hour washout period. In the primary efficacy analysis, there were significant differences favoring both doses of dapoxetine compared with placebo for increasing IELT (p<.OOO1). At the end of treatment, mean IELT was 2.06 minutes in the placebo group compared with 2.93 minutes for dapoxetine, 60 mg, and 3.20 minutes for dapoxetine, 100 mg.
Efficacy was immediate, as well. After the first dose, mean change from baseline IELT was 0.33 minutes for placebo; 1.52 minutes for dapoxetine, 60 mg; and 1.39 minutes for dapoxetine, 100 mg (60 mg vs. placebo, p.0l4; 100 mg vs. placebo, p.025).
Ten patients — one taking placebo and nine receiving dapoxetine, 100 mg – withdrew from the study due to adverse events. However, the 60-mg dose of dapoxetine was well tolerated and associated with a relatively low incidence of minor side effects.
Based on the phase II results, phase III studies were conducted to investigate dapoxetine, both 30 mg and 60 mg, and some preliminary results from those investigations are encouraging, said lead author Wayne J.G. Hellstrom, MD, professor of urology und chief, section of androiogy, at Tulane University Health Sciences Center in New Orleans.
“Considering the favorable efficacy and safety profile demonstrated so far for dapoxetine, we look forward to this novel agent as being the first medication approved by the FDA for the treatment of premature ejaculation,” he said.