We know that ejaculation delay is one of the secondary effects of selective serotonin reuptake inhibitors (SSRI) use, so these products are sometimes used off label in premature ejaculation in order to exploit this characteristic. Long-acting SSRI require however long-term therapies which can cause negative side effects, like a decrease in libido or erection disorders. So, a short-acting SSRI has been marketed, dapoxetine, with the indication to treat premature ejaculation on demand. In two randomized three-month studies, sponsored by pharmaceutical industry, 2600 men (average age 40; 87% white men) suffering from moderate or severe premature ejaculation for 15 years at least were treated with dapoxetine (30-60 mg) or placebo, to be taken from 1 to 3 hours before a sexual intercourse. All subjects had regular partners and an intravaginal ejaculation time of 2 minutes or less (measured by their partners with a chronometer). At the beginning of the study, the average time was 0.9 minutes. After the first dose, time increased with placebo, with the lower dose and with the higher dose of dapoxetine respectively up to 1.4, 2.1 and 2.4 minutes. After 12 weeks of treatment, time was 1.8, 2.8 and 3.3 minutes. In the three groups, 14%, 29% and 34% of males had reached an intravaginal ejaculation time higher than 3 minutes. Differences between the two dosages of dapoxetine and placebo are statistically significant. The perception of ejaculation control and the satisfaction of patient and partner were improved too. Side effects included nausea, diarrhoea, headache and dizziness, but few participants interrupted the study.
Dapoxetine seems to have very good possibilities for on demand treatment of premature ejaculation. For the moment, however, FDA has not yet approved its use in this indication.
