Two-drug regimen effective for premature ejaculation

Paris-A combination regimen of tadalafil (Cialis) and slow-release fluoxetine (Prozac) can significantly prolong intravaginal ejaculation latency time (IELT) in patients suffering from premature ejaculation (PE), according to Brazilian researchers.

Rogerio M. Mattos MD, a urologist at the Institute of Urology, University of Sao Paulo, and his team of researchers conducted a prospective, randomized, double-blind study with tadalafil, a phosphodiesterase type-5 inhibitor, and slow-release fluoxetine, a selective serotonin reuptake inhibitor, to increase IELT in patients suffering from premature ejaculation. He presented the study's results at the European Association of Urology annual congress here.

"Patients who took a 20-mg dosage of tadalafil in a 36-hour window prior to sexual intercourse and combined it with a once-weekly dosage of 90 mg of fluoxetine in a slow-release form showed a significant increase in their intravaginal ejaculation latency time from baseline compared to either drug taken individually. This combination therapy proved to be very beneficial to these patients, greatly increasing sexual satisfaction and sparing them the need to be medicated on a daily basis," Dr. Mattos explained.

Patients were followed for 12 weeks, with the IELT being timed with a stopwatch before the beginning of treatment and weekly during the treatment period. Patients were medicated with fluoxetine, 90 mg, or placebo once each week and tadalafil, 20 mg, or placebo 36 hours before sexual intercourse with their female partner.

Significant differences

Mean IELT was 55 seconds before treatment initiation among all four groups. The greatest increase in time from baseline IELT was seen in the group of patients who received a combined regimen of tadalafil and fluoxetine (mean, 464.41 seconds, p<.01). The mean increase in IELT in the group who received fluoxetine only was 230.98 seconds (p<.01), and 207.11 seconds (p<.01) for those who received tadalafil only.

Dr. Mattos said side effects were minimal and occurred equally in all groups of patients who took part in the study.

Patients had to fill out the IIEF questionnaire 3 weeks prior to initiation of the study and at completion of the study in order to exclude them from erectile dysfunction. The baseline IELT was also established at this time point.

Dr. Mattos was asked during his presentation whether the PDE-5 inhibitor directly affected the ejaculatory mechanism.

"I am not certain at this time concerning its exact effect. A similar study completed by Dr. McMahon (J Sex Med 2005; 2:368-75) showed that when only sildenafil was administered to patients, it did not affect the ejaculatory mechanism," Dr. Mattos responded, referring to a study by Chris McMahon, MB, BS, of the Australian Centre for Sexual Health, Sydney. "I am not sure if tadalafil could have a central effect to produce a lengthening of the IELT, but probably better erections had an effect on these patients, as well."