Antidepressants and ejaculation: a double-blind, randomized, fixed-dose study with mirtazapine and paroxetine.

A double-blind, fixed-dose study in healthy men with lifelong early ejaculation was performed to evaluate potential differences in their effects on ejaculation latency, between clinically relevant doses of the selective serotonin reuptake inhibitor paroxetine and the noradrenergic and specific serotonergic antidepressant mirtazapine. Twenty-four men with an intravaginal ejaculation latency time (IELT) less than 1 minute were randomly assigned to paroxetine (20 mg/d) or mirtazapine (30 mg/d) for a period of 6 weeks; half the dosage was given in the first week. During the preceding 1-month baseline and 6-week treatment period, intravaginal ejaculation latency times were measured at home using a stopwatch procedure. The trial was completed by 18 men. Analysis of variance revealed a between-group difference in the development of the delay in intravaginal ejaculation latency time over time (P < 0.001); the intravaginal ejaculation latency time after paroxetine and mirtazapine gradually increased from 15 to 119 s and from 23 to 28 s, respectively, after 6 weeks. Paroxetine 20 mg/d exerted a strong delay (maximum 5.7-fold increase), whereas mirtazapine 30 mg/d did not delay ejaculation (0.9-fold increase). These results confirm earlier findings that paroxetine, but not mirtazapine, significantly delays orgasm and ejaculation in men with early ejaculation, whereas mirtazapine is devoid of any effect on it.