From the Guidelines
Fluoxetine's efficacy for treating premature ejaculation typically lasts for the duration of treatment, with effects generally beginning after 1-2 weeks of daily use and continuing as long as the medication is taken. The standard dosage ranges from 5-20mg daily, with 5-20 mg/day being the reported effective dose for delaying ejaculation and enhancing patient/partner satisfaction 1. Once treatment is discontinued, the effects on ejaculation latency usually diminish within days to weeks as the medication is cleared from the body. Fluoxetine works by increasing serotonin levels in the brain, which helps delay ejaculation by modulating the ejaculatory reflex.
Key Points to Consider
- Patients should be aware that this is an off-label use of fluoxetine, and side effects may include decreased libido, erectile dysfunction, fatigue, and nausea.
- For optimal results, the medication should be taken consistently at the same time each day.
- Some clinicians recommend on-demand dosing (taking the medication prior to sexual activity), but daily dosing provides more consistent results.
- Treatment duration varies based on individual response, with some patients requiring several months of therapy while others may benefit from longer-term management.
Important Considerations
- The choice of regimen often is based upon the frequency of sexual activity by the patient.
- The optimal interval for situational dosing before intercourse has not been established and the onset of action of these SRIs for this indication is unknown.
- Adverse event profiles may differ among patients depending on the regimen prescribed, with doses that are effective in the treatment of PE usually being lower than those recommended in the treatment of depression, suggesting that the frequency and severity of adverse events also could be less 1.
From the Research
Duration of Efficacy of Fluoxetine for Premature Ejaculation
The duration of efficacy of fluoxetine for treating premature ejaculation can be understood through various studies that have examined the effects of fluoxetine on intravaginal ejaculatory latency time (IELT) and other parameters related to premature ejaculation.
- Short-term Efficacy: Studies have shown that fluoxetine can significantly improve IELT and ejaculatory control in men with premature ejaculation 2, 3. For example, a study found that fluoxetine increased the geometric mean IELT to about 110 seconds after 6 weeks of treatment 2.
- Long-term Efficacy: However, the long-term efficacy of fluoxetine for premature ejaculation is less clear. A study found that dropout rates at 6 and 12 months were 56% and 72%, respectively, suggesting that compliance with fluoxetine treatment may be poor over time 4. Despite this, the study found that self-rated "poor" ejaculatory control decreased from 98% to 41% after 12 months of treatment.
- Comparison with Other Treatments: Fluoxetine has been compared with other treatments for premature ejaculation, including tadalafil and sildenafil. A study found that the combination of fluoxetine and tadalafil significantly increased IELT compared to placebo, tadalafil, or fluoxetine alone 5. Another study found that fluoxetine combined with sildenafil provided better ejaculatory latency time and intercourse satisfaction compared to fluoxetine alone 3.
- Predictors of Continued Use: Predictors of continued use of fluoxetine for premature ejaculation include high partner distress, being unpartnered, and having a post-treatment IELT ≥5 minutes 4.
Overall, fluoxetine appears to be an effective treatment for premature ejaculation in the short term, but its long-term efficacy may be limited by poor compliance. Further studies are needed to fully understand the duration of efficacy of fluoxetine for premature ejaculation.