Carbamazepine with Nimodipine Interaction Details
Brand Names Associated with Carbamazepine
- Carbamazepine
- Carbatrol®
- Epitol®
- Equetro®
- Tegretol®
- Tegretol®-XR
- Teril®
Brand Names Associated with Nimodipine
- Nimodipine
- Nimotop®
- Nymalize®

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 25, 2023
Interaction Effect
Reduced nimodipine plasma concentrations and reduced nimodipine efficacy
Interaction Summary
A single study has shown that concurrent use of enzyme inducing antiepileptic agents (phenytoin, phenobarbital, and carbamazepine) with nimodipine has resulted in decreased nimodipine levels. Concomitant use of carbamazepine (a CYP3A4 inducer) and nimodipine (a CYP3A4 substrate) should be avoided. Concurrent use may significantly decrease nimodipine plasma levels, and may result in reduction of antihypertensive effects of nimodipine .
Severity
Major
Onset
Delayed
Evidence
Probable
How To Manage Interaction
Concomitant use of carbamazepine and nimodipine should be avoided. Concurrent use may significantly decrease nimodipine plasma levels and may result in reduction of antihypertensive efficacy.
Mechanism Of Interaction
Induction of CYP3A4-mediated metabolism of nimodipine by carbamazepine
Literature Reports
A) Three groups of eight subjects were studied . Group 1 was comprised of healthy subjects, group 2 had epileptic patients treated at least four months with carbamazepine, phenobarbital, phenytoin (all enzyme inducers), or a combination, and group 3 included epileptic patients treated for at least four months with sodium valproate. Compared to the control group, nimodipine AUCs averaged a 7-fold decrease in the enzyme inducer group, probably due to induction of first-pass metabolism. The nimodipine AUCs were increased by 50% in the valproate-treated group.
Carbamazepine Overview
-
Carbamazepine is used alone or in combination with other medications to control certain types of seizures in people with epilepsy. It is also used to treat trigeminal neuralgia (a condition that causes facial nerve pain). Carbamazepine extended-release capsules (Equetro brand only) are also used to treat episodes of mania (frenzied, abnormally excited or irritated mood) or mixed episodes (symptoms of mania and depression that happen at the same time) in patients with bipolar I disorder (manic-depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Carbamazepine is in a class of medications called anticonvulsants. It works by reducing abnormal electrical activity in the brain.
Nimodipine Overview
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Nimodipine is used to decrease brain damage that may be caused by a subarachnoid hemorrhage (bleeding in the space surrounding the brain that occurs when a weakened blood vessel in the brain bursts). Nimodipine is in a class of medications called calcium channel blockers. It works by relaxing blood vessels in the brain to allow more blood to flow to damaged areas.
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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.