Naproxen Dosing for Heavy Menstrual Bleeding
For heavy menstrual bleeding, naproxen should be prescribed at 500 mg initially, followed by 250 mg every 6-8 hours (or 500 mg every 12 hours), taken only during the 5-7 days of active menstrual bleeding, with a maximum daily dose not exceeding 1250 mg on the first day and 1000 mg thereafter. 1, 2, 3
Recommended Dosing Regimen
NSAIDs, including naproxen, are the first-line pharmacologic treatment for heavy menstrual bleeding according to the American College of Obstetricians and Gynecologists and the Centers for Disease Control and Prevention. 1, 2
Specific Naproxen Dosing:
- Initial dose: 500 mg naproxen at onset of bleeding 3
- Maintenance: 500 mg every 12 hours OR 250 mg every 6-8 hours 3
- Maximum first day dose: 1250 mg 3
- Maximum subsequent days: 1000 mg daily 3
- Duration: 5-7 days during active menstrual bleeding only 1, 2, 4
Evidence of Effectiveness
Naproxen has demonstrated significant reductions in menstrual blood loss across multiple studies:
- In women with IUD-associated heavy bleeding (>80 mL per cycle), naproxen reduced menstrual blood loss by 22-32% compared to placebo 5
- Nearly 60% of naproxen-treated cycles resulted in menstrual blood loss below 80 mL 5
- In women with documented hypermenorrhea (average 133 mL/cycle), naproxen 250 mg three times daily reduced bleeding by 42.8% in the first treatment cycle 6
- Multiple NSAIDs including naproxen have shown statistically significant reductions in mean menstrual blood loss 7, 2, 8
Critical Contraindications and Warnings
Screen for cardiovascular disease before prescribing naproxen, as NSAIDs are contraindicated in women with cardiovascular disease due to increased risk of myocardial infarction and thrombosis. 1, 2, 4
- Avoid in: Active cardiovascular disease, history of MI, stroke, or significant cardiovascular risk factors 1, 2
- Renal impairment: Not recommended in moderate to severe renal impairment (creatinine clearance <30 mL/min) 3
- Elderly patients: Use lowest effective dose due to increased unbound plasma fraction 3
Important Clinical Considerations
- Avoid aspirin for heavy menstrual bleeding—it does not reduce bleeding and may paradoxically increase blood loss in women with lower baseline menstrual blood loss 2, 4
- Timing matters: Naproxen sodium formulation is preferred when rapid onset of pain relief is desired due to faster absorption 3
- Treatment duration: Limit to 5-7 days during active bleeding only; continuous use is not necessary or recommended 1, 2
- Use lowest effective dose for the shortest duration consistent with treatment goals 3
When NSAIDs Fail or Are Contraindicated
If naproxen is ineffective after 2-3 cycles or contraindicated:
- Consider levonorgestrel-releasing IUD (LNG-IUD): Most effective long-term treatment, reducing menstrual blood loss by 71-95% 1, 2
- Tranexamic acid: Reduces blood loss by approximately 80 mL per cycle, but absolutely contraindicated in women with thromboembolic disease or cardiovascular disease 2, 4
- Combined oral contraceptives or estrogen: 10-20 day courses may be effective as second-line therapy if medically eligible 4
Special Population: LNG-IUD Users with Breakthrough Bleeding
For women using LNG-IUD experiencing breakthrough bleeding, naproxen administered for 5-7 days during bleeding episodes resulted in a 10% reduction in bleeding and spotting days compared to placebo 9. The naproxen group was significantly more likely to be in the lowest quartile of bleeding days (42.9% vs 16.3% for placebo) 9.