Can combined oral contraceptives (COCs) be used to treat menstrual cramps?

Combined Oral Contraceptives for Menstrual Cramps

Combined oral contraceptives are effective for treating menstrual cramps (dysmenorrhoea), with high-quality evidence showing moderate pain reduction compared to placebo. 1

Evidence for Effectiveness

COCs reduce menstrual pain through multiple mechanisms: they suppress ovulation, decrease endometrial thickness, reduce menstrual fluid volume, and lower prostaglandin production, which collectively decrease uterine contractions and cramping. 2, 1

Pain Relief Outcomes

• High-quality evidence demonstrates that COCs provide moderate pain reduction (standardized mean difference -0.58,95% CI -0.74 to -0.41) compared to placebo or no treatment. 1

• Women using COCs are 65% more likely to experience pain improvement compared to placebo (risk ratio 1.65,95% CI 1.29 to 2.10), meaning if 28% of women improve with placebo, 37-60% will improve with COCs. 1

• COCs reduce the need for additional pain medication (risk ratio 0.63,95% CI 0.40 to 0.98) and decrease absence from work or school (risk ratio 0.63,95% CI 0.41 to 0.97). 1, 3

Recommended Formulations

Start with a monophasic low-dose COC containing 30-35 μg ethinyl estradiol combined with levonorgestrel or norgestimate as first-line therapy. 4, 3

• Low-dose pills (≤35 μg ethinyl estradiol) are recommended as first-line options for treating dysmenorrhoea. 4

• Second-generation progestins like levonorgestrel have a safer coagulation profile compared to newer progestins. 3

• Among low-dose formulations, there is no clear evidence that one is superior to another for most users, so the lowest copay option on insurance formulary is often appropriate. 3

Extended/Continuous Regimens for Severe Symptoms

For women with severe dysmenorrhoea, continuous use of COCs (skipping placebo pills) may provide superior pain relief compared to standard 21/7 regimens. 1, 3

• Continuous regimens reduce pain more effectively than standard regimens (standardized mean difference -0.73,95% CI -1.13 to -0.34). 1

• Extended or continuous cycles are particularly useful for conditions exacerbated cyclically, providing optimized ovarian suppression and decreased menstrual cramping. 3, 5

• The most common adverse effect of extended-cycle regimens is unscheduled bleeding, which does not indicate treatment failure and typically improves with continued use. 3, 5

Initiation Protocol

COCs can be started on the same day as the visit ("quick start") in healthy, non-pregnant individuals. 4, 3

• Use backup contraception (condoms or abstinence) for the first 7 days if contraceptive efficacy is needed. 4

• If starting more than 5 days after menstrual bleeding began, backup contraception is necessary for 7 days. 3

• Blood pressure measurement is recommended before initiation. 5

• A pelvic examination is not required before starting COCs. 4

Safety Considerations and Adverse Effects

COCs probably increase the risk of adverse events compared to placebo, but the absolute risks remain low. 1

• Irregular bleeding is the most common side effect, occurring in 39-60% of users compared to 18% with placebo (risk ratio 2.63,95% CI 2.11 to 3.28). 1

• COCs probably increase headaches (risk ratio 1.51,95% CI 1.11 to 2.04) and nausea (risk ratio 1.64,95% CI 1.17 to 2.30). 1

• The risk of venous thromboembolism increases from 1 per 10,000 to 3-4 per 10,000 woman-years with COC use, which is still significantly lower than the 10-20 per 10,000 risk during pregnancy. 4, 3

• Weight gain and mood changes have not been reliably linked to COC use. 4

Contraindications

Do not prescribe COCs for patients with:

• Severe uncontrolled hypertension (systolic ≥160 mm Hg or diastolic ≥100 mm Hg) 4
• Migraines with aura or focal neurologic symptoms 4
• Thromboembolism or thrombophilia (factor V Leiden, antiphospholipid antibody syndrome, protein C/S deficiency) 4
• Ongoing hepatic dysfunction or complicated valvular heart disease 4
• Complications of diabetes (nephropathy, retinopathy, neuropathy, vascular disease) 4

Common Pitfalls

• Seven consecutive days of hormone pills are necessary to reliably prevent ovulation - extending the hormone-free interval beyond 7 days increases ovulation risk. 4, 5

• Smoking is not a contraindication to COC use in individuals younger than 35 years old, though it should be discouraged. 3

• If two or more consecutive pills are missed (≥48 hours), take the most recent missed pill, continue the pack, and use backup contraception for 7 days. 4, 5

• Reassure patients that common transient adverse effects like irregular bleeding, headache, and nausea typically improve with continued use - enhanced counseling about expected bleeding patterns reduces method discontinuation. 4, 6