New drug for the treatment of premature ejaculation has great results

May 24 2005

In new data published this week it has been shown that men taking dapoxetine hydrochloride for the treatment of premature ejaculation (PE) have experienced significant improvements in sexual function, including ejaculatory control, satisfaction with sexual intercourse for men and their partners, and increases in intravaginal ejaculatory latency time (IELT).

A new drug application for dapoxetine is currently under review by the U.S. Food and Drug Administration (FDA), and if approved, it will be the first prescription product indicated for the treatment of PE.

Premature ejaculation may be the most common male sexual disorder according to the American Urological Association, they estimate that PE may affect 27% to 34% of men across all age ranges, in contrast to erectile dysfunction, which is estimated to affect 10% to 12% of all men, who are usually older in age.

But although PE is common it still remains widely under-diagnosed and under-treated. Most physicians do not screen for PE and patients are very reluctant to talk about the condition with their partners or health care professionals. PE can have a significant impact on many aspects of a man's life. It can affect his and his partner's sexual satisfaction and their ability to build and maintain relationships, both sexual and non-sexual, and can impact a man's general sense of self confidence.

Jon L. Pryor, M.D., chairman and program director of the Department of Urologic Surgery at the University of Minnesota and lead investigator of the dapoxetine phase III clinical trials, says PE can be a lifelong condition experienced from the beginning of sexual activity or can develop after years of satisfactory sexual activity. He says the impact it can have on men and their partners can be devastating for a relationship and there are no truly optimal therapies for PE at present, and these latest results with dapoxetine are compelling.

Pryor says it demonstrates that, for the first time, a medicine can be taken by men on an on-demand basis and provide significant improvement in their PE condition, and the unique profile of dapoxetine translated into targeted treatment of PE compared to existing therapies.

The phase III clinical trials studied 2,614 men with PE aged 18-77 in monogamous sexual relationships of longer than six months. PE was defined as persistent or recurrent ejaculation sooner than desired either before or shortly after penetration, typically reflecting an IELT of two minutes or less, over which the sufferer has minimal or no control.

Men in the studies were randomly selected to receive 30 mg or 60 mg of dapoxetine over 12 weeks in two identical, double-blind, placebo-controlled, multicenter trials. Patients were asked to take the medication one-to-three hours before intercourse. Participants had IELT of two minutes or less in at least 75% of intercourse episodes occurring during the two-week baseline run-in period prior to treatment.

The studies examined changes from baseline for mean IELT as monitored by a stopwatch; measured the subject's ejaculatory control and sexual satisfaction on a five-point scale from "very poor to very good"; and measured the partner's satisfaction with sexual intercourse from "very poor to very good". The results showed that the men taking dapoxetine 30 mg and 60 mg experienced more than a three-to- four fold increase in mean IELT compared with placebo, and IELT increased significantly with the first dose of dapoxetine, and increases in IELT were maintained over the 12-week study period.

The percentage of men rating control over ejaculation as "fair to very good" increased dramatically for dapoxetine 30 mg (2.5% to 51.8%) and 60 mg (3.3% to 58.4%) compared to placebo (3.5% to 26.4%).

The percentage of men rating sexual satisfaction as "good to very good" almost doubled with dapoxetine 30 mg (20.2% to 38.7%) and 60 mg (22.3% to 46.5%), respectively, in comparison to placebo (21.6% to 24.6%).

The percentage of partners rating sexual satisfaction as "good to very good" almost doubled with dapoxetine 30 mg (20.4% to 39%) and 60 mg (24.8% to 47.4%), respectively, compared to placebo (20.1% to 25.2%).

It was also found that dapoxetine was generally well tolerated, with most side effects of mild-to-moderate severity. The most common adverse events reported with both 30 mg and 60 mg doses of dapoxetine were nausea, followed by headache.

The data was presented at the 100th Annual Scientific Meeting of the American Urological Association.