First-Line Contraceptive Oral Contraceptive Pills
Combined oral contraceptive pills (COCs) containing ethinyl estradiol 35 μg or less with levonorgestrel or norethindrone are considered first-line OCPs due to their effectiveness, relatively low risk of venous thromboembolism, and availability on prescription benefits programs. 1
Recommended First-Line OCPs
Low-Dose Combined Hormonal Contraceptives
- Monophasic pills containing ethinyl estradiol 20-35 μg combined with a first or second generation progestin:
- Ethinyl estradiol 20 μg/levonorgestrel 100 μg (low-dose option)
- Ethinyl estradiol 30-35 μg/levonorgestrel or norethindrone
Effectiveness
- First-line COCs have a typical-use failure rate of 5-9% but perfect-use failure rates as low as 0.1% 2, 3
- Ethinyl estradiol/levonorgestrel 20 μg/100 μg has demonstrated a Pearl index of 0.88 pregnancies per 100 woman-years 4
Rationale for First-Line Selection
Safety Profile
- First and second generation progestins (levonorgestrel, norethindrone) combined with low-dose ethinyl estradiol (≤35 μg) have the most favorable risk profile among combined hormonal methods 5
- These formulations have a relatively lower risk of venous thromboembolism compared to newer generation progestins 5
- Baseline VTE risk in non-users: 1 per 10,000 woman-years
- Risk with COCs: 3-4 per 10,000 woman-years 6
Blood Pressure Considerations
- Low-dose ethinyl estradiol formulations have less impact on blood pressure than higher-dose options 5
- Studies comparing BP among individuals taking COCs with varying doses of first, second, and third generation progestins have not observed significant differences in BP elevations between groups 5
Newer Options to Consider
- Drospirenone-containing pills (fourth generation progestin) may be beneficial for patients with hypertension concerns:
- Demonstrated decreases in systolic blood pressure due to anti-mineralocorticoid effects 5
- However, these are not considered first-line due to higher VTE risk compared to levonorgestrel-containing pills
Important Contraindications and Precautions
Absolute Contraindications
- History of venous thromboembolism or arterial thrombotic disease
- Breast or endometrial carcinoma
- Undiagnosed abnormal genital bleeding
- Severe hypertension
- Diabetes with vascular involvement
- Migraine with aura
- Liver tumors
- Age ≥35 years who smoke 6
Drug Interactions
- Effectiveness may be reduced when used with:
- Anticonvulsants
- Some antimicrobials
- HIV protease inhibitors
- St. John's wort 5
- Ritonavir-boosted protease inhibitors, nevirapine, and efavirenz can reduce hormonal levels, potentially decreasing contraceptive effectiveness 5
Clinical Pearls
- Before prescribing, obtain thorough personal and family history of thrombotic events, measure blood pressure, screen for migraine with aura, assess for liver disease, and consider age and smoking status 6
- For patients with higher BMI, consider higher estrogen doses or alternative methods as effectiveness may be reduced 6
- Progestin-only pills (POPs) are an alternative for patients with contraindications to estrogen-containing methods, with perfect-use failure rates of 0.5% 2
- Extended-cycle regimens (fewer or no inactive pills) may be beneficial for conditions like anemia, severe dysmenorrhea, endometriosis, and migraines without aura 6
Remember that while these first-line options are recommended based on safety and effectiveness, individual factors including medical history, risk factors, and preferences should guide the final selection.