Does current scientific and clinical evidence support the use of phosphodiesterase type 5 inhibitors for the treatment of premature ejaculation? a systematic review and meta-analysis.

INTRODUCTION: Premature ejaculation (PE) is a highly prevalent and complex syndrome that remains poorly defined and inadequately characterized. Pharmacotherapy represents the current basis of lifelong PE treatment. AIM: The goal of this study was to assess the role of phosphodiesterase type 5 inhibitors (PDE5-Is) in the treatment of patients with PE without associated erectile dysfunction (ED). MAIN OUTCOME MEASURE: The posttreatment intravaginal ejaculatory latency time was used as the primary end point of efficacy. METHODS: A systematic review of the literature was performed by electronically searching the MedLine database for peer-reviewed articles regarding the mechanism of action and the clinical trials of PDE5 in the management of PE. A meta-analysis of these clinical studies was performed to pool the efficacy. RESULTS: Twenty-nine articles that examined the supposed mechanisms of action and 14 articles that reported data from clinical studies were reviewed. The PDE5 may exert their influence by increasing the levels of nitric oxide both centrally (reducing sympathetic drive) and peripherally (leading to smooth-muscle dilatation of the seminal tract). These drugs may also induce peripheral analgesia to prolong the duration of the erection, increase confidence, improve the perception of ejaculatory control and overall sexual satisfaction, and decrease the postorgasmic refractory time for achieving a second erection after ejaculation. Concerning the efficacy, the meta-analysis shows an overall positive effect for the use of PDE5 as monotherapy or as components of a combination regimen in the treatment of PE. The major limitations of the published literature included poor study design, the absence of solid methodology, which was characterized by the lack of a unique PE definition, and the lack of appropriate endpoints for outcome evaluation of a placebo control arm and of Institutional Review Board approval. CONCLUSION: There is inadequate, partial basic, and clinical evidence to support the use of PDE5 for the treatment of PE.