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

Area of Science:

• Pharmacology
• Urology
• Psychiatry

Background:

• Premature ejaculation (PE) is a common sexual dysfunction affecting men's quality of life.
• Selective serotonin reuptake inhibitors (SSRIs) and noradrenergic and specific serotonergic antidepressants (NaSSAs) are classes of drugs with potential effects on ejaculatory function.

Purpose of the Study:

• To compare the efficacy of paroxetine (an SSRI) and mirtazapine (a NaSSA) in delaying ejaculation latency in men with lifelong PE.
• To evaluate potential differences in the effects of clinically relevant doses of paroxetine and mirtazapine on ejaculation latency.

Main Methods:

• A double-blind, fixed-dose study was conducted with 24 healthy men diagnosed with lifelong PE (intravaginal ejaculation latency time < 1 minute).
• Participants were randomly assigned to receive either paroxetine 20 mg/day or mirtazapine 30 mg/day for 6 weeks, with a dose titration in the first week.
• Intravaginal ejaculation latency times (IELT) were self-measured at home using a stopwatch during a 1-month baseline and the 6-week treatment period.

Main Results:

• A significant difference in the development of IELT delay was observed between the two groups (P < 0.001).
• Paroxetine treatment resulted in a significant increase in IELT, from a baseline of 15 seconds to 119 seconds after 6 weeks (a 5.7-fold increase).
• Mirtazapine treatment showed a minimal increase in IELT, from 23 seconds to 28 seconds (a 0.9-fold increase), indicating no significant delay in ejaculation.

Conclusions:

• Paroxetine at a dose of 20 mg/day effectively delays ejaculation and orgasm in men with lifelong PE.
• Mirtazapine at a dose of 30 mg/day does not demonstrate a significant effect on delaying ejaculation in men with PE.
• These findings confirm the efficacy of paroxetine and the lack of efficacy of mirtazapine in managing premature ejaculation.