Carbamazepine with Miconazole Interaction Details
Brand Names Associated with Carbamazepine
- Carbamazepine
- Carbatrol®
- Epitol®
- Equetro®
- Tegretol®
- Tegretol®-XR
- Teril®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 25, 2023
Interaction Effect
Increased carBAMazepine exposure
Interaction Summary
The concomitant use of carBAMazepine (a CYP3A4 substrate) and a CYP3A4 inhibitor may increase the exposure of carBAMazepine. If carBAMazepine is used concomitantly with a CYP3A4 inhibitor, closely monitor carBAMazepine levels and adjust the carBAMazepine dosage as required.
Severity
Moderate
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
If carBAMazepine (a CYP3A4 substrate) is used concomitantly with a CYP3A4 inhibitor, closely monitor carBAMazepine levels and adjust the carBAMazepine dosage as required.
Mechanism Of Interaction
Inhibition of CYP3A4-mediated metabolism of carBAMazepine
Literature Reports
A) The addition of fluvoxaMINE to a constant dosage of carBAMazepine in 3 patients caused an increase in carBAMazepine levels, resulting in symptoms of toxicity . However, no increase in carBAMazepine levels in 8 epileptic patients who were given fluvoxaMINE 100 mg daily or fluoxetine 20 mg daily with carBAMazepine for 3 weeks .
B) Concomitant administration of verapamil 120 mg orally 3 times a day in patients receiving carBAMazepine for refractory partial epilepsy was reported to result in carBAMazepine neurotoxicity in all of 6 patients treated. Increase in free and total carBAMazepine levels were observed in 5 patients (mean increases of 33% and 46%, respectively) associated with a concurrent decrease by 36% in the ratio of carBAMazepine-10,11 epoxide to carBAMazepine. Symptoms resolved after several days following withdrawal of verapamil in all patients. Rechallenge in 2 patients resulted in similar neurotoxic symptoms. Reductions in the dose of carBAMazepine may be required when verapamil is administered and then increased when verapamil is withdrawn to avoid exacerbation of epileptic seizures. Seizure aggravation occurred in 1 patient in this series following abrupt withdrawal of verapamil .
C) In a 24-year-old woman with intractable epilepsy, the patient's complex-partial seizures had been refractory to multiple anticonvulsants, partial temporal lobectomy, and vagal nerve stimulation; this resulted in intermittent hospitalization a mean of every 55 days for management of complex partial status epilepticus. Verapamil 180 mg/day was added to an anticonvulsant regimen composed of carBAMazepine 600 mg twice daily in addition to levETIRAcetam, topiramate, and clonazePAM. Baseline carBAMazepine plasma concentration level was at the low end of the therapeutic range (4.2 mg/mL). At 1-month follow-up, carBAMazepine plasma concentration was 7.4 mg/L, and the patient reported subjective improvement in seizure control. Verapamil dose was titrated incrementally up to 480 mg daily, resulting in an increase in carBAMazepine plasma concentration to 13.3 mg/L, without report of adverse effects and with an extension to approximately 4 months between hospital admissions .
D) Cimetidine 400 mg 3 times daily significantly increased steady-state carBAMazepine plasma levels by 17% after 2 days. However, carBAMazepine levels decreased to pretreatment levels by the seventh day of cimetidine treatment. CarBAMazepine side effects appeared in most patients within 24 hours following cimetidine initiation, but subsided over the next 48 to 72 hours. The investigators concluded that dosage adjustments appear unnecessary, but that patients should be warned of the appearance of carBAMazepine side effects for the first 3 to 5 days after beginning cimetidine .
E) A case of carBAMazepine toxicity was reported in an elderly man receiving carBAMazepine 200 mg 3 times daily, isoniazid 300 mg daily, and cimetidine 400 mg twice daily. Two days after initiating this drug combination, the patient developed nausea, vomiting, dizziness, and epigastric pain. CarBAMazepine serum concentrations were elevated. Patients receiving this combination of therapy should have close monitoring of carBAMazepine concentrations .
F) Concomitant carBAMazepine and dilTIAZem administration may produce elevated serum carBAMazepine levels, resulting in neurotoxicity . In a case report, dilTIAZem 60 mg 3 times daily elevated the carBAMazepine level by 40% higher than baseline, resulting in clinical signs of carBAMazepine toxicity. NIFEdipine 20 mg 3 times daily did not produce any adverse effect . In another case report, a patient with a stable carBAMazepine dose (800 mg daily) and serum concentration (8.5 to 10.1 mg/L) was started on dilTIAZem 30 mg 3 times a day for atrial fibrillation. Approximately 2 weeks later, the patient was admitted to the hospital with mental slowing and speech difficulties. The serum carBAMazepine level the next day was 15.5 mg/L. CarBAMazepine was consequently reduced to 300 mg daily, which produced a serum level of 8.3 mg/L and resolution of the mental disturbances .
Carbamazepine Overview
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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.
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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.