But FDA Approval Appears Unlikely for Dapoxetine Soon, Despite Promising Studies
By Salynn Boyles
WebMD Health News
Latest MedicineNet News
Reviewed By Louise Chang, MD
on Thursday, September 07, 2006
Men in the study who took the experimental drug Dapoxetine, developed by Johnson & Johnson Pharmaceuticals in conjunction with ALZA Corp., were able to maintain erections longer than men who took placebos.
Dapoxetine is a selective serotonin reuptake inhibitor (SSRI) but is slightly different from the SSRIs (such as Zoloft, Paxil, and Prozac) widely prescribed for depression and other psychiatric disorders.
The drug was designed to be taken as needed, one to three hours before sex, instead of every day. Also, it is eliminated from the body more quickly than other SSRIs.
Hopes that Dapoxetine would become the first drug approved for premature ejaculation dimmed last October, when the FDA sent a "not approvable" letter to the manufacturer.
The FDA's concerns about the drug were not made public. In a news release, ALZA Corp. promised to "address questions raised in the FDA letter."
A spokesperson for Johnson & Johnson told WebMD Thursday that the company "remains committed to the global development" of Dapoxetine.
A Common Complaint
Although it is rarely talked about, premature ejaculation is a common problem, affecting as many as a third of men.
Far fewer men seek treatment, however.
Those who do are often advised on practice techniques to help. Some receive a prescription for a traditional, long-acting SSRI, since delayed ejaculation is a common side effect among men who take SSRIs for depression.
This use of traditional SSRIs would be considered off-label since the medications are not specifically indicated for this problem.
Other potential sexual side effects of SSRIs include erectile dysfunction and loss of libido, however, making the traditional antidepressants less than ideal for treatment of premature ejaculation, Jon L. Pryor, MD, tells WebMD. Pryor is a urology professor at the University of Minnesota.
In the manufacturer-funded study, Pryor and colleagues compared 30-milligram and 60-milligram doses of Dapoxetine to a placebo in roughly 2,600 men with moderate to severe premature ejaculation.
Prior to treatment, the men's average ejaculation time was just under a minute.
With treatment, the average time to ejaculation was 1.75 minutes in the placebo-treated men, 2.78 minutes in the men treated with 30 milligrams of Dapoxetine, and 3.32 minutes in the men treated with 60 milligrams of the drug. The study lasted three months.
"A couple of minutes may not sound like much but for these guys it was huge," Pryor says.
Men who took the short-acting SSRI also reported having more control over their ejaculations than the placebo-treated men; and they and their female partners reported improved sexual satisfaction.
The Snicker Factor
Pryor says an effective, specific treatment could do for premature ejaculation what Viagra did for erectile dysfunction -- taking away the 'snicker' factor by stimulating open discussion about the disorder.
"Viagra wasn't a magic pill, but it did bring ED into the open and men who had it learned that they were not alone," he says. "The discussion that followed stimulated research that led to other treatments.
"Premature ejaculation is more common than ED, but no one talks about it," adds Pryor.
Ira Sharlip, MD, a urology professor at the University of California, San Francisco, tells WebMD there is a definite need for an effective treatment for premature ejaculation.
"I have patients who are really disturbed by this issue, and so are their wives," he says. "The current treatments are far from perfect."
Sharlip says traditional SSRIs work best when they are taken every day, and even then they only work for around two-thirds of patients.
"Premature ejaculation is certainly one of the most common forms of sexual dysfunction among men," Sharlip says. "Not everyone who has it is bothered by it, but for those who are, it can be a very big problem."
SOURCES: Pryor, J. The Lancet, Sept. 9, 2006; vol 368: pp 929-937. Jon L. Pryor, MD, Department of Urologic Surgery, University of Minnesota, Minneapolis. Ira Sharlip, MD, spokesman, American Urological Association; professor of urology, University of California, San Francisco. Interview with spokesperson for Johnson & Johnson Pharmaceuticals. Susan Cruzan, spokeswoman, FDA.
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