Can fluoxetine (selective serotonin reuptake inhibitor) be used to treat premature ejaculation, or is paroxetine (selective serotonin reuptake inhibitor) preferred?

Fluoxetine for Premature Ejaculation Treatment

Yes, fluoxetine at 5-20 mg/day is an effective and appropriate treatment option for premature ejaculation, though paroxetine (10-40 mg/day) is often considered more effective according to current guidelines. 1, 2

SSRI Options for Premature Ejaculation

The American Urological Association guidelines and recent clinical practice summaries support the use of several SSRIs for treating premature ejaculation:

• Fluoxetine: 5-20 mg/day
• Paroxetine: 10-40 mg/day (or 20 mg 3-4 hours before intercourse)
• Sertraline: 25-200 mg/day (or 50 mg 4-8 hours before intercourse)
• Clomipramine: 25-50 mg/day (or 25 mg 4-24 hours before intercourse)

While all these medications are effective, paroxetine has shown the greatest benefit in delaying ejaculation according to clinical evidence, with the majority of evidence supporting 20 mg daily dosing. 1, 2

Dosing Approaches

Two main dosing strategies exist:

1. Daily dosing: More consistent effect but higher risk of side effects

   • Fluoxetine: 5-20 mg/day
   • Paroxetine: 10-40 mg/day

2. Situational (on-demand) dosing: Less medication used but may be less effective

   • Paroxetine: 20 mg 3-4 hours before intercourse
   • Fluoxetine: Not typically used situationally due to pharmacokinetics

Many clinicians, including panel members from the American Urological Association, utilize situational dosing in their practices, sometimes after an initial period of daily dosing. 1

Efficacy Considerations

• Fluoxetine at 5-20 mg/day has been shown to effectively delay ejaculation and enhance patient/partner satisfaction compared to placebo. 1, 3
• In comparative studies, the combination of fluoxetine with tadalafil has shown significant increases in intravaginal ejaculatory latency time (IELT). 3
• However, paroxetine has demonstrated particularly strong efficacy in treating PE, with significant improvements in ejaculatory control. 4, 5

Important Clinical Considerations

1. Duration of therapy: Treatment is typically needed on a continuing basis, as PE usually returns upon discontinuation of medication. 1, 2

2. Compliance challenges: Despite effectiveness, compliance with fluoxetine beyond 6 months is poor, with studies showing dropout rates of 56% at 6 months and 72% at 12 months. 6

3. Side effects: Common side effects include:

   • Headache (5%)
   • Dizziness (4%)
   • Nausea (5%)
   • Nervousness (5%)
   • Sleepiness (8%)
   • Sexual side effects (decreased libido: 6-15% with paroxetine) 7, 6

4. FDA approval status: None of these medications are FDA-approved specifically for premature ejaculation treatment in the US. 2

Treatment Algorithm

1. Initial assessment: Confirm PE diagnosis and rule out erectile dysfunction (ED), as PE may improve once ED is effectively managed.

2. First-line treatment:

   • For daily therapy: Start with fluoxetine 5-20 mg/day or paroxetine 10-20 mg/day
   • For situational therapy: Paroxetine 20 mg 3-4 hours before intercourse

3. Monitoring: Assess treatment efficacy using patient and partner satisfaction and ejaculatory latency time.

4. Dose adjustment: If inadequate response after 2-4 weeks, consider:

   • Increasing fluoxetine to 20 mg/day (maximum)
   • Switching to paroxetine if fluoxetine is ineffective
   • Adding behavioral therapy for enhanced results

5. Long-term management: Discuss the need for continued therapy, as benefits typically disappear upon discontinuation.

Conclusion for Benjamin's Case

For Benjamin who is currently on fluoxetine 20 mg for PE with good response and no side effects, continuing his current regimen is appropriate. While paroxetine may offer slightly better efficacy based on guidelines, changing medication when he has a good response without side effects is unnecessary and could disrupt his current treatment success.