Efficacy of type-5 phosphodiesterase inhibitors in the drug treatment of premature ejaculation: a systematic review.

This review examines the role of nitric oxide (NO) as a neurotransmitter involved in the central and peripheral control of ejaculation, the methods of phosphodiesterase type 5 inhibitor (PDE5I) drug treatment studies for premature ejaculation (PE), the adherence of methods to the contemporary consensus of ideal PE drug trial design, the impact of methods on treatment outcomes and the role of PDE5Is in the treatment of PE. NO/cGMP transduction is involved in both the central and peripheral control of emission, but evidence for a direct central or peripheral effect of PDE5Is on ejaculation is speculative. Thirteen of the 14 studies reviewed failed to fulfil the evidence-based medicine criteria for ideal PE drug trial design.