What is the recommended low-dose combined oral contraceptive (COC) regimen for treating dysmenorrhea?

Low-Dose Combined Oral Contraceptives for Dysmenorrhea

Start with a monophasic COC containing 30-35 μg ethinyl estradiol combined with levonorgestrel or norgestimate as first-line therapy for dysmenorrhea. 1, 2

Recommended Formulations

• The American Academy of Pediatrics recommends beginning with 30-35 μg ethinyl estradiol combined with a second-generation progestin (levonorgestrel or norgestimate) as the preferred initial regimen. 1, 2

• Any "low-dose" pill containing ≤35 μg ethinyl estradiol can be used effectively for dysmenorrhea, though formulations with 30-35 μg provide more reliable ovarian suppression than ultra-low-dose (20 μg) options. 1, 2

• Second-generation progestins (levonorgestrel, norgestrel) demonstrate a safer coagulation profile compared to third- and fourth-generation progestins, making them the preferred choice when thrombotic risk is a consideration. 2

Evidence for Efficacy

• High-quality evidence from a 2023 Cochrane review demonstrates that COCs provide moderate pain reduction compared to placebo (standardized mean difference -0.58), with women experiencing 37-60% improvement in pain versus 28% with placebo. 3

• Specific low-dose formulations proven effective include 35 μg ethinyl estradiol with 1 mg norethisterone and 20 μg ethinyl estradiol with 150 μg desogestrel, both showing significant reductions in dysmenorrhea scores and pain intensity. 4, 5

• Pain improvement typically begins by cycle 2 and continues through subsequent cycles, with concurrent reductions in analgesic use (from 100% to 41% of women) and interference with daily activities (from 73% to 10%). 4, 5

Initiation Protocol

• Start COCs on the same day as the visit using the "quick start" method in healthy, non-pregnant patients. 1, 2

• Instruct patients to use backup contraception (condoms or abstinence) for the first 7 days to ensure contraceptive efficacy. 1, 2

• No gynecologic examination is required to determine eligibility for COC use, though screening for sexually transmitted infections is recommended in sexually active patients. 1

• The CDC recommends prescribing up to 1 year of COCs at a time to improve adherence. 1, 2

Continuous vs. Cyclic Regimens

• Continuous use regimens (no hormone-free interval) may provide superior pain control compared to standard 21/7 cyclic regimens for dysmenorrhea. 3

• Continuous regimens reduce pain more effectively than standard regimens (standardized mean difference -0.73), though they carry similar adverse effect profiles. 3

• The most common adverse effect of continuous regimens is unscheduled breakthrough bleeding, which typically improves with continued use. 2, 3

Expected Adverse Effects

• COCs probably increase the risk of any adverse events compared to placebo (RR 1.31), with the most common being irregular bleeding (RR 2.63), headaches (RR 1.51), and nausea (RR 1.64). 3

• The absolute risk of venous thromboembolism increases from 1 per 10,000 to 3-4 per 10,000 woman-years during COC use—still significantly lower than the 10-20 per 10,000 risk during pregnancy. 1, 2

• Adverse effects typically decrease over time with continued use, and most transient effects (irregular bleeding, headache, nausea) resolve within the first few months. 1, 4

Absolute Contraindications

• Do not prescribe COCs for patients with: severe uncontrolled hypertension (≥160/100 mm Hg), ongoing hepatic dysfunction, complicated valvular heart disease, migraines with aura or focal neurologic symptoms, current or history of thromboembolism or thrombophilia, or complications of diabetes (nephropathy, retinopathy, neuropathy). 1, 2

• Smoking is not a contraindication to COC use in women younger than 35 years old, though smoking cessation should be encouraged. 1, 2

Follow-Up and Monitoring

• Schedule a follow-up visit 1-3 months after initiating COCs to address adverse effects or adherence issues. 1, 2

• If dysmenorrhea persists despite 3 cycles of COC use, consider switching to a continuous regimen or evaluating for secondary causes of dysmenorrhea. 3

• Blood pressure monitoring is the primary safety requirement for women on long-term COC therapy and should be performed regularly throughout treatment. 2

Clinical Pearls

• Among low-dose formulations, there are no clear data suggesting one is superior to another for most users, so selecting the lowest copay option on a patient's insurance formulary is appropriate. 2

• COCs provide additional benefits beyond dysmenorrhea treatment, including decreased menstrual blood loss, improvement in acne, and long-term protection against endometrial and ovarian cancers with >3 years of use. 1, 2

• If two or more consecutive hormonal pills are missed, use backup contraception until hormonal pills have been taken for 7 consecutive days. 2, 6