What supplements should be avoided when taking Oral Contraceptive Pills (OCP)?

Supplements to Avoid When Taking Oral Contraceptive Pills

Certain supplements and medications should be avoided when taking oral contraceptive pills (OCPs) as they can reduce contraceptive effectiveness, particularly those that induce liver enzymes or disrupt the gut absorption of hormones.

Supplements That Reduce OCP Effectiveness

St. John's Wort

• Must be avoided with all hormonal contraceptives 1
• Classified as Category 2 risk for all hormonal contraceptive methods
• Induces liver enzymes that metabolize estrogen and progestin, reducing their effectiveness

Enzyme-Inducing Supplements

Similar to enzyme-inducing medications, these supplements can reduce OCP effectiveness:

• Herbal preparations containing:
  • Wild yam
  • Black cohosh
  • Red clover
  • Dong quai
  • Evening primrose oil

Medications That Reduce OCP Effectiveness

Anticonvulsants

• Certain anticonvulsants are classified as Category 3 (risks generally outweigh benefits) 1:
  • Phenytoin
  • Carbamazepine
  • Barbiturates
  • Primidone
  • Topiramate
  • Oxcarbazepine
• Lamotrigine is also Category 3 when used as monotherapy with combined OCPs 1

Antimicrobials

• Rifampicin/rifabutin are Category 3 with OCPs 1
  • Significantly reduces OCP effectiveness
  • Alternative contraception recommended for long-term users

Antiretroviral Therapy

• Ritonavir-boosted protease inhibitors are Category 3 with combined hormonal contraceptives 1
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are Category 2 1

Specific Supplement Interactions

Aprepitant

• Used for cyclic vomiting syndrome
• May interfere with oral contraceptive pills 1
• Consider alternative contraception if using this medication

Clinical Recommendations

1. For patients taking enzyme-inducing medications or supplements:

   • Use a higher-dose OCP containing at least 30 μg ethinyl estradiol 1
   • Consider alternative contraceptive methods
   • Use condoms as backup contraception

2. For patients taking broad-spectrum antibiotics:

   • Most do not affect OCP effectiveness (Category 1) 1
   • However, individual cases of breakthrough bleeding have been reported 2
   • Consider backup contraception during short-term antibiotic use if concerned

3. For patients taking antifungals or antiparasitics:

   • No clinically significant interactions with OCPs (Category 1) 1

4. For patients with headaches:

   • OCPs may worsen headaches in some users 3
   • Consider lower-dose estrogen formulations (≤20 μg ethinyl estradiol) 4

Monitoring

• Schedule follow-up 1-3 months after starting OCPs to assess for adverse effects 4
• Monitor for breakthrough bleeding, which may indicate reduced effectiveness
• Consider alternative contraception methods if taking interacting supplements long-term

Remember that drug interactions with OCPs primarily affect contraceptive effectiveness, potentially leading to unintended pregnancy. When in doubt about a specific supplement interaction, using a backup method of contraception is the safest approach.