The role of local anaesthetics in premature ejaculation

Abstract

What's known on the subject? and What does the study add? It is now accepted that both biological and psychological factors are important in the aetiology of premature ejaculation (PE). Of particular interest is the correlation between ejaculatory latency and penile sensory thresholds. Men with PE appear to have a heightened sensory response to penile stimulation and also generally exhibit other abnormal reflex pathways within the ejaculatory process, suggesting a link between penile hypersensitivity and PE. Considering these sensory differences, drugs that selectively produce some degree of penile desensitization or act within the afferent-efferent reflex could delay ejaculatory latency without adversely affecting the sensation of ejaculation. This review evaluates published clinical trial data for local anaesthetics used off-label in PE as well as novel topical agents in development. New analyses of the phase III data are presented for topical eutectic mixture for PE (TEMPE, also known as PSD502, Plethora Solutions Plc., London), a proprietary formulation of lidocaine and prilocaine in a metered-dose aerosol delivery system.

Objectives: • To review the published clinical trial data for local anaesthetics used off-label in premature ejaculation (PE), as well as novel topical agents in development. • To evaluate the safety and efficacy of topical eutectic mixture for PE (TEMPE) in subjects with PE and their sexual partners using all available phase III data.

Results: • Topical treatments can be applied as needed and systemic side-effects are unlikely. However, existing off-label topical treatments for PE have several disadvantages: they can be messy, interfere with spontaneity, and could cause numbness in the man or his partner. • Several novel topical agents are in development for the treatment of PE. TEMPE appears to be closest to approval. • TEMPE, applied 5 min before sexual intercourse (539 subjects) resulted in an increase in the geometric mean intra-vaginal ejaculatory time (IELT) from a baseline of 0.58 min to 3.17 min during 3 months of double-blind treatment; a 3.3-fold delay in ejaculation compared with placebo (P < 0.001). • IELT continued to increase further with continued use of TEMPE throughout the double-blind and open-label phases. • Treatment with TEMPE also resulted in marked improvements in subjective measures, e.g. ejaculatory control, sexual satisfaction and distress, with little or no evidence of systemic side-effects and minimal desensitization of the genitalia in subjects or their sexual partners.

Conclusions: • The use of a topical agent could be an acceptable first-line option for PE, given the favourable risk/benefit ratio of these products. • Topical aerosol application of TEMPE may provide safe, effective, on-demand treatment for PE.