Carbamazepine with Acetylcysteine 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
Subtherapeutic carbamazepine levels
Interaction Summary
One woman experienced decreased carbamazepine trough levels three days after starting N-acetylcysteine therapy, which led to three consecutive tonic-clonic seizures. It was proposed that high doses of N-acetylcysteine may increase the clearance of carbamazepine and its metabolites to inactive derivatives, leaving the patient at an increased risk for seizure activity. Closely monitor carbamazepine levels in patients also receiving N-acetylcysteine.
Severity
Moderate
Onset
Delayed
Evidence
Probable
How To Manage Interaction
Use caution when prescribing N-acetylcysteine to patients who take carbamazepine. Concomitant use of N-acetylcysteine and carbamazepine may cause decreased carbamazepine plasma concentrations resulting in an increased risk of seizures. Closely monitor carbamazepine levels in patients also receiving N-acetylcysteine.
Mechanism Of Interaction
Increased clearance of carbamazepine
Literature Reports
A) A 59-year-old female being treated for two years with carbamazepine 800 mg daily had serum trough levels above 10 mcg/mL. Lamotrigine was added to her therapeutic regimen to allow a slow withdrawal of carbamazepine. As the dose of lamotrigine increased to 75 mg daily, the patient developed fever, lymphadenopathy, conjunctivitis, and maculopapular eruptions on the face and upper torso. Carbamazepine trough level at this time was 11.1 mcg/mL. The patient was diagnosed with lamotrigine-induced hypersensitivity, and N-acetylcysteine 2 g every six hours was initiated with rapid clinical improvement. However, on the third day of N-acetylcysteine therapy, the patient had three tonic-clonic seizures within five hours. Although her carbamazepine dose had not changed, the trough level was 8.1 mcg/mL. It was proposed that the high doses of N-acetylcysteine increased the clearance of carbamazepine and its metabolites to inactive derivatives, leaving the patient at an increased risk for seizure activity .
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.
Return To Our Drug Interaction Homepage
Feedback, Question Or Comment About This Information?
Ask Dr. Brian Staiger, PharmD, our medical editor, directly! He's always more than happy to assist.
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.