What is the best type of Combined Oral Contraceptive (COC)?

Best Type of Combined Oral Contraceptive (COC)

The best type of COC is one containing low-dose ethinyl estradiol (≤35 μg) with either levonorgestrel or norgestimate as the progestin component, as these formulations provide effective contraception with the lowest risk of venous thromboembolism. 1

Factors to Consider When Selecting a COC

Estrogen Component

• Ethinyl estradiol (EE) dose:
  • Low-dose COCs containing ≤35 μg EE are recommended for most women
  • Ultra-low dose (10-20 μg EE) may be appropriate for some women but may have more breakthrough bleeding 2
  • Higher doses of EE (>35 μg) are associated with increased VTE risk and are no longer commonly prescribed 1

Progestin Component

• First-line progestins:

  • Levonorgestrel (2nd generation) - lowest VTE risk among progestins 3
  • Norgestimate (3rd generation) - also has favorable VTE risk profile 1
  • Norethindrone (1st generation) - also considered first-line 1, 4

• Other progestins with higher VTE risk:

  • Drospirenone (4th generation) - may have up to 1.5-1.8 times higher VTE risk compared to levonorgestrel 3
  • Desogestrel (3rd generation) - higher VTE risk than levonorgestrel 3

Venous Thromboembolism (VTE) Risk Considerations

VTE risk is a critical factor in COC selection:

• Baseline VTE risk in non-pregnant, non-COC users: 1-5 per 10,000 woman-years
• COC users (general): 3-9 per 10,000 woman-years
• Drospirenone-containing COC users: approximately 10 per 10,000 woman-years 1
• For comparison, pregnancy-associated VTE risk: 5-20 per 10,000 woman-years 1

Benefits Beyond Contraception

COCs offer several non-contraceptive benefits:

• Decreased menstrual cramping and blood loss
• Improvement in acne (particularly with anti-androgenic progestins)
• Reduced risk of endometrial and ovarian cancers with long-term use 1
• Management of conditions like dysmenorrhea, endometriosis, and abnormal uterine bleeding

Special Considerations

For Patients with Acne

• Four FDA-approved COCs for acne treatment:
  • Norgestimate/EE
  • Norethindrone acetate/EE/ferrous fumarate
  • Drospirenone/EE
  • Drospirenone/EE/levomefolate 1
• Drospirenone has anti-androgenic properties but carries higher VTE risk 1, 3

For Patients with Migraine

• COCs are contraindicated in women with migraine with aura due to increased stroke risk
• Ultra-low dose formulations (<20 μg EE) may be better tolerated in women with migraine without aura 5

For Adolescents

• Many adolescent medicine experts recommend starting with 30-35 μg EE with levonorgestrel or norgestimate 1
• Counseling about side effects and proper use is essential for adherence

Dosing Regimens

• Standard regimen: 21-24 active pills followed by 4-7 placebo pills
• Extended or continuous regimens: May be beneficial for conditions like endometriosis, dysmenorrhea, or when menstrual suppression is desired 1

Common Pitfalls to Avoid

1. Prescribing high-dose estrogen formulations: Modern low-dose formulations (≤35 μg EE) provide effective contraception with lower risk of adverse effects

2. Ignoring VTE risk factors: Additional risk factors (smoking, obesity, family history of VTE) should be considered when prescribing COCs 3

3. Overlooking drug interactions: Some medications (certain anticonvulsants, antibiotics like rifampin) can reduce COC effectiveness 1

4. Switching between brand-name and generic formulations: This may affect bioavailability and increase breakthrough bleeding, potentially leading to discontinuation 6

5. Inadequate counseling about side effects: Common transient side effects include irregular bleeding, headache, and nausea; proper counseling improves adherence 1

In conclusion, when selecting a COC, prioritize formulations containing ≤35 μg ethinyl estradiol with levonorgestrel or norgestimate for the optimal balance of efficacy and safety for most women.