Nifedipine with Mibefradil Interaction Details
Brand Names Associated with Nifedipine
- Adalat®
- Adalat® CC
- Afeditab® CR
- Nifedical® XL
- Nifedipine
- Nifeditab® CR
- Procardia®
- Procardia® XL
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 20, 2023
Interaction Effect
Severe bradycardia and hypotension
Interaction Summary
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 hypertension.
Severity
Major
Onset
Rapid
Evidence
Probable
How To Manage Interaction
Allow seven days to elapse between the discontinuation of mibefradil and the initiation of NIFEdipine therapy.
Mechanism Of Interaction
Additive calcium channel blockade
Literature Reports
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 .
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 .
Nifedipine Overview
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Nifedipine is used to treat high blood pressure and to control angina (chest pain). Nifedipine is in a class of medications called calcium-channel blockers. It lowers blood pressure by relaxing the blood vessels so the heart does not have to pump as hard. It controls chest pain by increasing the supply of blood and oxygen to the heart.
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High blood pressure is a common condition and when not treated, can cause damage to the brain, heart, blood vessels, kidneys and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.