Does Rifampin Interact with Norethindrone Acetateethinyl Estradiol?
Rifampin and Norethindrone Acetateethinyl Estradiol have a major drug interaction according to U.S. FDA drug labeling data. Rifampin increases metabolism of norethindrone and ethinyl estradiol, reducing contraceptive effectiveness and increasing breakthrough bleeding and menstrual irregularities. The mechanism involves increased metabolism of both active ingredients. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Major
- Rifampin Class
- Rifamycin Antibacterial
- Norethindrone Acetateethinyl Estradiol Class
- Estrogen
- Management
- Close medical supervision required
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Rifampin and Norethindrone Acetateethinyl Estradiol occurs because increased metabolism of both active ingredients. Clinically, this means rifampin increases metabolism of norethindrone and ethinyl estradiol, reducing contraceptive effectiveness and increasing breakthrough bleeding and menstrual irregularities. This is classified as a major interaction, meaning it could cause serious harm if not properly managed. Your healthcare provider may need to adjust dosages, substitute one medication, or increase monitoring frequency.
What To Tell Your Doctor or Pharmacist
If you are taking Rifampin and your doctor is considering prescribing Norethindrone Acetateethinyl Estradiol (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask how frequently you should be monitored while these are co-prescribed
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider