Cardiovascular Safety Profile of Dapoxetine during the Premarketing Evaluation

The cardiovascular safety profile of dapoxetine, a novel selective serotonin reuptake inhibitor (SSRI) developed as an on-demand oral treatment for premature ejaculation (PE) in men, is evaluated. The cardiovascular assessment of dapoxetine was conducted throughout all stages of drug development, with findings from preclinical safety pharmacology studies, phase I clinical pharmacology studies investigating the effect of dapoxetine on QT/corrected QT (QTc) intervals in healthy men, and phase III, randomized, placebo-controlled studies evaluating the safety (and efficacy) of the drug. Preclinical safety pharmacology studies did not suggest an adverse electrophysiologic or hemodynamic effect with concentrations of dapoxetine up to 2-fold greater than recommended doses. Phase I clinical pharmacology studies demonstrated that dapoxetine did not prolong the QT/QTc interval and had neither clinically significant electrocardiographic effects nor evidence of delayed repolarization or conduction effects, with dosing up to 4-fold greater than the maximum recommended dosage. Phase III clinical studies of dapoxetine in men with PE indicated that dapoxetine was generally safe and well tolerated with the dosing regimens used (30mg and 60mg as required). Events of syncope were reported during the clinical development program, with the majority occurring during study visits (on site) on day 1 following administration of the first dose when various procedures (e.g. orthostatic maneuvers, venipunctures) were performed, suggesting that the procedures contributed to the incidence of syncope. This was consistent with previous reports showing that these and similar factors contribute to or trigger vasovagal syncope. Findings of the dapoxetine development program demonstrate that dapoxetine is associated with vasovagal-mediated (neurocardiogenic) syncope. No other associated significant cardiovascular adverse events were identified.