Nifedipine and Mibefradil: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Nifedipine
Mibefradil
No brand names on record
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
Severe bradycardia and hypotension
Interaction Deep Dive
Two case reports describe severe hypotension and bradycardia in patients who took NIFEdipine the day after discontinuing mibefradil therapy. Mibefradil has a half-life of 17 to 25 hours. Therefore, a washout period of seven days should elapse after the discontinuation of mibefradil before therapy with a different calcium channel blocker should be considered. In addition, since mibefradil blocks both T (transient) and L (long) calcium channels, other available calcium channel blockers which only block L-type calcium channels are unlikely to be more effective at controlling hypertension1.
Why it happens (mechanism)
Additive calcium channel blockade
Literature reports
2 reports — tap to read
a) A 79-year-old female receiving mibefradil 100 mg daily and propranolol 160 mg daily continued to have poorly controlled blood pressure. Mibefradil was discontinued, and the next day therapy with NIFEdipine extended-release 60 mg was started. One hour after the first dose of NIFEdipine, she collapsed and was brought to an emergency department with a systolic blood pressure of 60 mm Hg and a junctional bradycardia at 40 to 50 beats per minute. Dopamine infusions did not significantly improve her status, and approximately 10 hours later she became unresponsive with a systolic blood pressure of 60 mm Hg and a junctional bradycardia at 40 to 50 beats per minute. Asystole followed and resuscitation was not successful. Autopsy results showed a normal heart with no evidence of acute myocardial infarction, aortic dissection, or pulmonary embolism 1.
b) A 60-year-old female continued to have poorly controlled hypertension despite treatment with mibefradil 100 mg daily and extended-release metoprolol 50 mg daily. Her medication regimen was switched to sustained-release NIFEdipine 60 mg daily, doxazosin 1 mg daily, and captopril 25 mg three times daily. A few hours later, she was admitted to the hospital with a systolic blood pressure of 70 mm Hg and a heart rate of 50 beats per minute. Twelve hours later, dopamine and norepinephrine infusions were being administered, and her blood pressure was 70/39 mm Hg while her heart rate was 60 beats per minute. Her bradycardia and hypotension gradually resolved over the next two days, and she was discharged from the hospital without residual effects 1.
Common questions
Can I take Nifedipine and Mibefradil together?
Severe bradycardia and hypotension Always confirm with your pharmacist or prescriber before making any change.
How serious is the Nifedipine and Mibefradil interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Nifedipine or Mibefradil 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 (1)
- Mullins ME, Horowitz BZ, Linden DHJ, et al: Life-threatening interaction of mibefradil and beta-blockers with dihydropyridine calcium channel blockers. JAMA 1998; 280:157-158.
Keep reading about Nifedipine
Keep reading about Mibefradil
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