Carbamazepine with Influenza Virus Vaccine 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 serum concentrations
Interaction Summary
Influenza vaccine has been reported to cause a decrease in the elimination and an increase in the half-life of carbamazepine, resulting in an increase in the carbamazepine plasma concentration. It has been proposed that the immune response after influenza vaccination may cause a depression of the cytochrome P450 isoenzymes responsible for oxidation of carbamazepine .
Severity
Moderate
Onset
Delayed
Evidence
Probable
How To Manage Interaction
The majority of patients might experience only a transient and slight increase in carbamazepine levels. No routine monitoring appears necessary.
Mechanism Of Interaction
Decreased cytochrome P450-mediated metabolism of carbamazepine
Literature Reports
A) In a study conducted on mentally retarded residents who were receiving single-drug anticonvulsant therapy, influenza vaccine resulted in increased levels of phenytoin, phenobarbital, and carbamazepine. Prior to vaccination, mean carbamazepine concentration was 6.17 mcg/mL. Serum carbamazepine concentrations were measured immediately prior to vaccination (day 0), and on days 7, 14, and 28. On day 7, the mean carbamazepine concentration had only increased to 6.89 mcg/mL. By day 14 and 28, concentrations had increased and decreased to 9.04 mcg/mL and 8.65 mcg/mL, respectively. Similar increases in plasma concentrations were observed in patients receiving phenobarbital and phenytoin. The proposed mechanism for the increased carbamazepine concentration is that influenza vaccine decreases the activity of hepatic enzymes which are responsible for carbamazepine metabolism .
B) Influenza vaccination may significantly increase carbamazepine blood levels. A report describes a case of carbamazepine toxicity that developed 13 days after administration of the influenza vaccine. A female 14 years, 11 months old complained of ataxia and increased lethargy. Her drug regimen included carbamazepine for partial complex seizures and gabapentin. Thirteen days prior to her complaints the patient received the inactivated influenza vaccine Fluzone(R), manufactured by Aventis Pasteur, Inc (Swiftwater, PA). Thirteen days later the child complained of nausea and subsequently vomited. She was dizzy, had slurred speech, became lethargic and poorly responsive. In the emergency department her CBZ level was 27.5 mcg/mL and a urine drug screen was positive for TCAs and cocaine. She was intubated, received IV fluids and activated charcoal. Four days after admission her CBZ level was 9.1 mcg/mL. The patient recovered and remains seizure free on her former dose of CBZ (400 mg am and 600 mg pm) and gabapentin (600 mg TID). The author concludes that the patients immune response after influenza vaccination caused a depression of the P450 isoenzymes responsible for oxidation of CBZ. This resulted in a rise in CBZ levels and observed CBZ toxicity. Some instances of CBZ toxicity may be secondary to inhibition of hepatic clearance by interferon production .
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.
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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.
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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.