April 26, 2009 -- An anesthetic spray for the penis, used five minutes before sex, helps men delay orgasm six times longer than usual.

The finding comes from a placebo-controlled clinical trial conducted by Plethora Solutions of London, England.

The 300 men in the study suffered from premature ejaculation. Their average time to ejaculation during sex -- as measured by their partners with a stopwatch -- was 36 seconds.

One-third of the men used a placebo spray with no active ingredients. Two-thirds used the anesthetic spray, called PSD502 (or TEMPE in a previous study), which delivers 7.5 milligrams of lidocaine and 2.5 milligrams of prilocaine to the head of the penis (and to the inside of the foreskin, for uncircumcised men).

After three months, placebo sprayers nearly doubled their time to ejaculation to 66 seconds. But those who used the real spray delayed orgasm for 228 seconds -- nearly four minutes.

After three months of spray treatment:

90% of the men in the treatment group vs. 54% of the men in the placebo group delayed ejaculation for more than one minute.

74% of the men in the treatment group vs. 22% of the men in the placebo group delayed ejaculation for more than two minutes.

62% of the treated men said their orgasms were good or very good. Only 20% said that before treatment. In the placebo group, orgasm satisfaction went down.

There were no serious side effects. 2.6% of the men in the treatment group (and 1% of the men in the placebo group) reported treatment-related adverse events.

Urologist Ira D. Sharlip, MD, a spokesman for the American Urological Association, says men who suffer premature ejaculation need new, more patient-friendly treatments.

"This new topical spray has promise to become one of the most effective treatments for premature ejaculation," Sharlip says in a news release. "It has a number of characteristics which will be attractive to patients with premature ejaculation."

Plethora co-founder Michael G. Wyllie reported the findings at this week's annual meeting of the American Urological Association in Chicago.