The metered-dose, aerosol spray is a mixture of the anesthetics lidocaine and prilocaine. It is spritzed onto the tip of the penis 15 minutes before sex.
Before using the spray, the 54 heterosexual men in the study ejaculated, on average, one minute after vaginal penetration.
In the test, on four occasions, half the men used the anesthetic spray 15 minutes before sex, the other half a placebo with no active ingredients.
The men or their partners used a stopwatch to measure the time from vaginal penetration to ejaculation.
- Lasting time increased to two minutes or more for 55% of the men who got the spray and 35% of the men who got the placebo.
- Lasting time increased to three minutes or more for 40% of the men who got the spray and 13% of the men who got the placebo.
- Lasting time increased to four minutes or more for 20% of the men who got the spray and 13% of the men who got the placebo.
- On average, men who got the spray lasted 2.4 times longer than those who got the placebo.
Premature ejaculation isn't defined by a specific time until ejaculation. According to the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV), premature ejaculation is "persistent or recurrent ejaculation with minimal sexual stimulation before, on, or shortly after penetration and before the person wishes it."
About 70% of men who used the spray and just under 50% of the men who used the placebo said they had longer time to ejaculation.
About 60% of the female partners of men who used the spray, and about 30% of the partners of the men who used the placebo, said the men had better control over their ejaculation.
The spray is called TEMPE -- topical eutectic mixture for premature ejaculation -- by manufacturer Plethora Solutions Ltd. London, which funded the study. It is not yet available on the market.
"TEMPE 'as required' has the potential to offer a convenient, novel treatment option for men with premature ejaculation," conclude researchers Wallace C. Dinsmore, MD, of Royal Victoria Hospital, Belfast, Northern Ireland, and colleagues.
The spray had few side effects.
Four of the 26 men who used TEMPE did report side effects. Three had numbness of the penis, and one reported erectile dysfunction.
Only one of the men's sex partners reported a side effect: a mild burning sensation during intercourse.
Emla, from AstraZeneca, is also a mixture of lidocaine and prilocaine. It comes in a cream formulation and must be used with a condom. TEMPE does not require condom use.
The study appears in the February issue of the urology journal BJU International.
SOURCES: Dinsmore, W. BJU International, February 2007; vol 99: pp 369-375. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.
By Daniel DeNoon
Reviewed by Louise Chang