What is the treatment for Premenstrual Dysphoric Disorder (PMDD) with Prozac (fluoxetine) for a partial month, specifically the week before menses?

Treatment of PMDD with Prozac (Fluoxetine) - Intermittent Luteal Phase Dosing

Fluoxetine 20 mg daily during the luteal phase (starting 14 days before expected menses through the first day of bleeding) is an effective and well-tolerated treatment for PMDD, with demonstrated superiority over placebo for mood, physical symptoms, and social functioning. 1

Recommended Dosing Regimens

Luteal Phase Daily Dosing (Preferred for Intermittent Treatment)

• Fluoxetine 20 mg daily starting 14 days before expected menses through the first full day of bleeding is the most effective intermittent regimen, showing significant improvement in mood symptoms, physical symptoms (breast tenderness, bloating, joint/muscle pain), and social functioning compared to placebo 1
• Fluoxetine 10 mg daily during the luteal phase showed less consistent efficacy and did not maintain statistical superiority to placebo throughout treatment cycles 1
• Treatment effects are evident by the first treatment cycle and remain consistent across subsequent cycles 1

Alternative Intermittent Regimen

• Enteric-coated fluoxetine 90 mg given twice during the luteal phase (at 14 days and 7 days before expected menses) demonstrated significant improvements in PMDD symptoms, mood, social functioning, and quality of life measures 2
• This weekly dosing regimen (90 mg twice per cycle) was superior to single-dose weekly administration and placebo 2

Continuous Daily Dosing

• Fluoxetine 20 mg daily throughout the entire menstrual cycle is also effective for PMDD and may be considered if luteal phase dosing proves insufficient 3
• Continuous dosing has been FDA-approved for PMDD treatment 3

Clinical Evidence Supporting Intermittent Dosing

The intermittent luteal phase approach is particularly attractive for PMDD because:

• 75% of women with PMDD respond to intermittent fluoxetine 20 mg daily during the luteal phase 4
• Discontinuation effects have not been reported with intermittent dosing regimens 3
• Treatment is well-tolerated with discontinuation rates due to adverse events not differing from placebo 1
• Reduces overall medication exposure compared to continuous dosing while maintaining efficacy 4

Symptom Response Profile

Fluoxetine luteal phase dosing effectively treats:

• Mood symptoms: depressed mood, anxiety, mood swings, irritability, sensitivity (significant improvement over placebo) 1
• Physical symptoms: breast tenderness, bloating, joint/muscle pain (20 mg dose shows superiority) 1
• Social functioning: improvements in work, family life, and social interactions 2

Practical Implementation

Timing Considerations

• Begin fluoxetine 14 days before the expected first day of menstruation 1
• Continue through the first full day of menstrual bleeding 1
• For women with irregular cycles, tracking ovulation or using calendar-based estimation may be necessary 3

Dose Selection

• Start with fluoxetine 20 mg daily during the luteal phase as this dose demonstrates consistent efficacy across all symptom domains 1
• Avoid 10 mg dosing for luteal phase treatment as it shows inconsistent efficacy 1
• Consider the 90 mg weekly regimen only if daily dosing compliance is problematic 2

Common Pitfalls to Avoid

• Do not use 10 mg luteal phase dosing: This dose failed to maintain statistical superiority over placebo throughout treatment and showed inferior efficacy for physical symptoms 1
• Ensure adequate treatment duration: Effects are seen by the first cycle, but three cycles of treatment were used in efficacy trials 1, 2
• Do not confuse PMDD with PMS: PMDD requires specific diagnostic criteria including severe mood symptoms that significantly impair functioning; treatment recommendations differ between these conditions 5

Comparison to Other Treatment Options

While SSRIs including sertraline (50-150 mg/d), escitalopram (10-20 mg/d), and paroxetine (12.5-25 mg/d) are also first-line treatments for PMDD, fluoxetine has the most extensive evidence base for intermittent luteal phase dosing specifically 5. Drospirenone-containing oral contraceptives represent an alternative first or second-line option depending on contraceptive needs 5.

Monitoring and Follow-up

• Assess response after the first treatment cycle, as improvement should be evident by this time 1
• Continue evaluation through at least three menstrual cycles to establish consistent benefit 1, 2
• Monitor for adverse events, though tolerability is generally excellent with intermittent dosing 3, 1