Medroxyprogesterone and Telaprevir: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Telaprevir
No brand names on recordMedroxyprogesterone
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Decreased contraceptive effectiveness
Interaction Deep Dive
Administration of telaprevir with ethinyl estradiol may significantly decrease plasma concentrations of ethinyl estradiol. Norethindrone concentrations were minimally effected. In a drug interaction study, concurrent administration of ethinyl estradiol and telaprevir led to significant decreases in ethinyl estradiol Cmax, AUC, and Cmin2. During concurrent use of telaprevir and combination contraceptives, 2 effective non-hormonal forms of birth control should be used throughout telaprevir therapy and until approximately 2 weeks following the discontinuation of telaprevir, at which time hormonal contraceptives may be used as 1 of the 2 contraceptive measures required during ribavirin and peginterferon alfa therapy; however, specific contraceptive prescribing guidelines should be followed. Patients who are using estrogens as hormone replacement therapy should be monitored for signs of estrogen deficiency 1.
Why it happens (mechanism)
Unknown
Literature reports
2 reports — tap to read
a) In a pharmacokinetic study (n=24), the concomitant administration of telaprevir 750 mg every 8 hours with an oral contraceptive containing ethinyl estradiol 0.035 mg and norethindrone 0.5 mg daily resulted in a 26% to 33% reduction in ethinyl estradiol exposure. Female volunteers 18 and 45 years old who were taking ethinyl estradiol 0.035 mg/norethindrone 0.5 mg for at least 3 months were enrolled. During the study, study participants received this combination contraceptive regimen for 21 days followed by a 7-day washout period, then ethinyl estradiol 0.035 mg/norethindrone 0.05 mg plus telaprevir for 21 days followed by telaprevir alone for 7 days. The mean Cmax, AUC at steady state, and Cmin for ethinyl estradiol decreased by 26%, 28% and 33%, respectively, after the administration of telaprevir. The least-squares mean ratios for ethinyl estradiol were all outside the no-effect boundaries of 0.8 to 1.25 (0.74 (90% confidence interval (CI); 0.68 to 0.80), 0.67 (90% CI; 0.63 to 0.71), and 0.72 (90% CI 0.69 to 0.75) for Cmax, Cmin, and AUC at steady state, respectively). Norethindrone and telaprevir exposures were found not to be significantly affected by the coadministration of both agents 2.
b) In 2 drug interaction studies (n=23 and n=24), administration of telaprevir 750 mg every 8 hours for 21 days concurrently with ethinyl estradiol 0.035 mg and norethindrone 0.5 mg daily for 21 days did not significantly change norethindrone concentrations. The norethindrone ratio estimate (norethindrone with telaprevir to norethindrone without) was 1 (90% confidence interval (CI), 0.93 to 1.07) for Cmax, 0.99 (90% CI, 0.93 to 1.05) for AUC and 1 (90% CI, 0.93 to 1.08) for Cmin for one study (n=23). In the second study (n=24), the ratio estimates were 0.85 (90% CI, 0.81 to 0.89), 0.89 (90% CI, 0.86 to 0.93), and 0.94 (0.87 to 1), respectively 1.
Common questions
Can I take Medroxyprogesterone and Telaprevir together?
Decreased contraceptive effectiveness Always confirm with your pharmacist or prescriber before making any change.
How serious is the Medroxyprogesterone and Telaprevir interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Medroxyprogesterone or Telaprevir need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: INCIVEK(TM) film coated oral tablets, telaprevir film coated oral tablets. Vertex Pharmaceuticals Incorporated, Cambridge, MA, 2011.
- Garg V, van Heeswijk R, Yang Y, et al: The pharmacokinetic interaction between an oral contraceptive containing ethinyl estradiol and norethindrone and the HCV protease inhibitor telaprevir. J Clin Pharmacol 2012; 52(10):1574-1583. PubMed
Keep reading about Telaprevir
Keep reading about Medroxyprogesterone
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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