The last study of the dapoxetine shows some secondary effects.

Introduction

Premature ejaculation is one of the most usual sexual dysfunctions among men. Selective inhibitors for the serotonine gaining (ISRS) have been used for that indication. Dapoxetine it’s an ISRS with a short-medium lifetime, developed for that use.

Objective

Study the efficiency and tolerance of dapoxetine at the treatment of fast eyaculation.

Study profile

  • Type of study: clinical essay
  • Area of the study: treatment
  • Ambit of the study: comunitary

Methods

In that study are reunited the results of two clinical essays ran with the same methodology. There were 2.614 patients with PE, that agreed with the principles of the DSM-IV, 16-year-old or more, with a stable couple, and lasting less than 2 minutes in the 75% of the relations they had the previous 2 weeks before the study.

Patinents with a erectile dysfunction were excluded, and also those who used any kind of ISRS or tricycles antidepressants, and those with psychiatrics illnesses, or under any other PE treatment or whose couple had feminine sexual dysfunction.

Randomly, to all the patients was distributed a placebo or dose of dapoxetine from 30 to 60 mg. It was recommended to all the patients having more than 6 sexual relations a month during the 12 weeks of the study and take the medicine 1-3 hours before that relation. Efficiency was measured on the 4th, 8th and 12th week. The main variable was the lasting time of the intravaginal ejaculation on the 12th week. As a secondary variable was used the score of the premature ejaculation profile, a questionnaire that rates the seriousness of the PE and how much satisfaction have the patient and his couple achieved during the sexual relations.

Results

2,614 patients participated in the study. There were no relevant differences among the participants of the 3 groups. The average age was 40 year old and the average duration of the problem was 16 years. In the 65% of the cases it was a primary PE.

The lasting time of the relation was increased in the 3 groups, but it was significantly higher in the groups that used dapoxetine, and also the dose of 60 mg was more efficient than the one of 30 mg. The percentage of patients that showed a lasting time higher than 3 minutes was also bigger in those who used the 60 mg dose, and of course still bigger than in those who only took a placebo. Differences appeared after the first dose and were independent of the seriousness of the PE. However it was recommended to take the medicine 1-3 hours befote the sexual relation, it was also efficient when taken Orly 30-60 minutes before it and more than 4 hours after swallowing it. The control degree of the ejaculation and the satisfaction also increased in the patients after taking dapoxetine.

Secondary effects that appeared more frequently affected to the digestive system (nausea, diarrea) and in the central nervous system (headache, dizziness, and somnolence). Nausea affected to the 20% of the patients that took a 60 mg dapoxetine dose. Those secondary effects made 5% of the patients give up on the treatment. The 3% of them who took dapoxetine suffered a sexual dysfunction, in comparison with the 1,5% that suffered that in the group of those who only took a placebo.

Conclusions

The authors concluded that dapoxetine is an efficient and well-tolerated treatment for PE.

Interest conflicts

Some of the authors received any kind of honorary from pharmaceutical laboratories.

Comentario

PE is one of the most frequent male sexual dysfunction. However, its frequency is not easy to establish, because there is not an accepted universal definition. The main measure for that problem is the lasting time of the relation (TLEI). Research made for studying its distribution among the population show that the TLEI has a right slanting distribution, with a central reservation of 5.4 min, with no objective measure to establish normality. The percentile 0.5 corresponds to the 0.9 min and the 2.5 with the 1.3 min. Based on those results, some authors set the definition of the PE in less than 1 min and probable in less than 1.5 minutes. The seriousness of that problem would be defined for the psychological issues associated to it.

Antidepressants like clomipramine or the ISRS are effective for delaying ejaculation in patients with PE, but some research say that the time needed between taking the medicine and the sexual relation was too long, which could be a handicap and also its use provoked many secondary effects after the took.

And so, it would be useful to have an ISRS with a quickest effect and a smaller life. Dapoxetine is an ISRS designed for that. In that study has been proved that it is a useful medicine. But there were those secondary effects and also we need to consider that the definition of PE was not the best (TLEI<2min.).

Bibliography

  • Waldinger MD, Zwinderman AH, Schweitzer DH, Olivier B. Relevance of methodological design for the interpretation of efficacy of drug treatment of premature ejaculation: a systematic review and meta-analysis. Int J Impot Res 2004; 16: 369-381.
  • Waldinger MD. Towards evidence-based drug treatment research on premature ejaculation: a critical evaluation of methodology. Int J Impot Res 2003; 15: 309-313.
  • Waldinger MD. Lifelong premature ejaculation: definition, serotonergic neurotransmission and drug treatment. World J Urol 2005; 23: 102-108.