How should I treat a reproductive‑age woman with typical primary dysmenorrhea and no red‑flag features?

Treatment of Primary Dysmenorrhea

Start with NSAIDs at the onset of menstrual pain using a loading dose (typically 800 mg ibuprofen), followed by regular dosing (400 mg every 4-6 hours) until symptoms resolve. 1, 2

First-Line Pharmacological Treatment: NSAIDs

NSAIDs are the mainstay of treatment for primary dysmenorrhea because they inhibit prostaglandin synthesis, which is the primary driver of uterine hypercontractility and pain. 2, 3, 4

Specific NSAID dosing strategy:

• Loading dose approach: Begin with 800 mg ibuprofen at the earliest onset of pain, then continue with 400 mg every 4-6 hours as needed. 1, 2
• Maximum daily dose: Do not exceed 3200 mg of ibuprofen per 24 hours. 1
• Duration of trial: Continue NSAID therapy for at least 3 menstrual cycles before determining treatment failure. 5, 2, 6
• Timing is critical: Start NSAIDs at the very first sign of menstrual pain or bleeding, not after pain is established. 2

Important caveat: If gastrointestinal complaints occur, administer ibuprofen with meals or milk to reduce GI irritation. 1

Second-Line Treatment: Hormonal Contraceptives

Add combined oral contraceptive pills (OCPs) if NSAIDs alone fail after 3 menstrual cycles. 5, 2, 6

The rationale for OCPs is that they suppress ovulation and reduce endometrial prostaglandin production. 2, 3 This approach is particularly appropriate for women who also desire contraception. 5, 3

Treatment duration: Trial OCPs for 3-6 menstrual cycles before reassessing. 5, 2, 6

When to Investigate for Secondary Causes

If dysmenorrhea does not improve within 3-6 months of combined NSAID and OCP therapy, investigate for secondary causes, particularly endometriosis. 5, 2

Red flags requiring earlier investigation:

• Dysmenorrhea that progressively worsens over time. 5
• Pain that begins before menstruation or persists after menstrual flow ends. 5
• Dysmenorrhea associated with abnormal bleeding patterns. 5
• Lack of response to appropriate first-line therapy. 5, 2

Diagnostic approach for suspected secondary dysmenorrhea:

• Obtain detailed history focusing on pain characteristics, timing, and associated symptoms. 5
• Perform pelvic examination (though often normal in adolescents with endometriosis). 5
• Order pelvic ultrasonography to evaluate for structural abnormalities. 5
• Consider laparoscopy if symptoms persist despite 6 months of medical therapy and no other etiology is identified. 5, 2

Alternative and Adjunctive Therapies

For women who cannot tolerate NSAIDs or hormonal contraceptives, or as adjuncts to pharmacological therapy, consider:

• Topical heat application to the lower abdomen. 3
• Transcutaneous electrical nerve stimulation (TENS). 3, 6
• Dietary supplements (though evidence is limited). 3, 6
• Acupuncture or acupressure (supporting studies are small with limited follow-up). 3, 4, 6

Common Pitfalls to Avoid

Do not wait to see if dysmenorrhea "gets better on its own" – approximately 10% of women with severe dysmenorrhea have underlying pelvic pathology such as endometriosis, which can progress if left untreated. 5, 2, 6

Do not delay investigation beyond 6 months of failed medical therapy – endometriosis in adolescents appears different than in adults (typically clear or red lesions rather than the classic "powder burn" appearance), and early diagnosis protects future fertility. 5

Do not prescribe NSAIDs to be taken "as needed" without specific instructions – the loading dose strategy is more effective than waiting for pain to become severe. 2

Do not assume all adolescent dysmenorrhea is primary – approximately 10% of cases have secondary causes, with endometriosis being the most common. 5, 2, 6

Treatment Algorithm Summary

1. Initial presentation: Start NSAIDs with loading dose strategy (ibuprofen 800 mg, then 400 mg every 4-6 hours) for 3 menstrual cycles. 1, 2

2. Inadequate response after 3 cycles: Add combined OCPs and continue for 3-6 cycles. 5, 2, 6

3. Persistent symptoms after 6 months of combined therapy: Investigate for secondary causes with pelvic ultrasound and consider laparoscopy. 5, 2

4. Throughout treatment: Assess adherence to therapy, as non-compliance is a common reason for apparent treatment failure. 5