Rifampin and Nifedipine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Rifampin
Nifedipine
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
Reduced NIFEdipine exposure and reduced efficacy of NIFEdipine
Interaction Deep Dive
Coadministration of NIFEdipine and strong CYP3A4 inducers is contraindicated, as concomitant use may significantly reduce NIFEdipine efficacy. In a study, (CYP3A4 substrate) and phenytoin (strong CYP3A4 inducer) coadministration reduced the AUC and Cmax of by approximately 70%1. Additional evidence suggests concomitant administration of NIFEdipine and strong CYP3A4 inducers may result in reduced effectiveness of NIFEdipine, including a study with St. John's wort 3 and a case report with rifAMPin 4. Consider alternate antihypertensive therapy 21.
Why it happens (mechanism)
Induction of CYP3A4-mediated metabolism of NIFEdipine
Literature reports
4 reports — tap to read
a) Coadministration of an oral dose of NIFEdipine (CYP3A4 substrate) and multiple oral doses rifAMPin (strong CYP3A4 inducer) significantly decreased NIFEdipine exposure in a clinical pharmacokinetic study. Healthy male volunteers (N=12) received a single oral dose of 20 mg NIFEdipine capsule on study Day 1. Starting on Day 2, subjects received 600 mg rifAMPin once daily for 14 days. On Day 15, a second single oral dose of 20 mg NIFEdipine capsule was administered together with the last dose of rifAMPin. Compared to Day 1, 14 days pretreatment with rifAMPin reduced Cmax and AUC of concomitantly administered NIFEdipine by a mean of 95% and 97%, respectively 1.
b) Coadministration of NIFEdipine 10 mg oral capsule and 60 mg NIFEdipine oral coat-core tablet with phenytoin (strong CYP3A4 inducer) decreased AUC and Cmax of NIFEdipine by approximately 70% 1.
c) St. John's wort (strong CYP3A4 inducer) reduced the mean plasma concentration of NIFEdipine in an open trial of 22 healthy subjects. Subjects received oral St. John's wort 900 mg/day for 18 days and then received a single oral dose of NIFEdipine 10 mg. The mean plasma concentration of NIFEdipine at 30 minutes was reduced by 53% compared with NIFEdipine alone (significance not stated) 3.
d) In a case report, a 75-year-old woman with hypertension had been well controlled with NIFEdipine. After she developed tuberculosis and was treated with rifAMPin (strong CYP3A4 inducer), both peak plasma concentration and AUC of NIFEdipine decreased to about 40% of previous levels and control of hypertension was significantly affected. Another calcium channel blocker, nisoldipine, was administered concurrently with rifAMPin, but it also was unable to lower her blood pressure 4.
Common questions
Can I take Rifampin and Nifedipine together?
Reduced NIFEdipine exposure and reduced efficacy of NIFEdipine Always confirm with your pharmacist or prescriber before making any change.
How serious is the Rifampin and Nifedipine interaction?
It is rated contraindicated. These should generally not be used together.
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 Rifampin or Nifedipine 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 (4)
- Product Information: NIFEDIPINE oral tablet, extended-release, nifedipine oral tablet, extended-release. Aurobindo Pharma Limited (per DailyMed), East Windsor, NJ, 2024. DailyMed
- Product Information: PROCARDIA XL(R) oral extended-release tablets, nifedipine oral extended-release tablets. Pfizer Labs (per Dailymed), New York, NY, 2023. DailyMed
- Smith M, Lin KM, & Zheng YP: An open trial of nifedipine-herb interactions: nifedipine with St. John's Wort, ginseng, or Ginkgo biloba (abstract). Clin Pharmacol Ther 2001; 69(2):P86.
- Tada Y, Tsuda Y, Otsuda T, et al: Case report: nifedipine-rifampin interaction attenuates the effect on blood pressure in a patient with essential hypertension. Am J Med Sci 1992; 303:25-27.
Keep reading about Rifampin
Keep reading about Nifedipine
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