Carbamazepine with Propoxyphene 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
An increased risk of carbamazepine toxicity (ataxia, nystagmus, diplopia, headache, vomiting, apnea, seizures, coma)
Interaction Summary
Concurrent propoxyphene therapy significantly increases carbamazepine concentrations and may result in moderate to severe neurotoxicity.
Severity
Major
Onset
Delayed
Evidence
Probable
How To Manage Interaction
Concurrent use of propoxyphene and carbamazepine should be avoided. Use of an alternative analgesic, such as a codeine or hydrocodone, should be considered. If concomitant therapy with propoxyphene and carbamazepine is required, closely monitor carbamazepine serum concentrations. Dosage reductions are likely to be necessary.
Mechanism Of Interaction
Decreased hepatic metabolism
Literature Reports
A) In an observational study of elderly patients, carbamazepine serum concentrations were significantly higher and carbamazepine side effects were significantly more common when propoxyphene was taken concomitantly. Patients who used both carbamazepine and propoxyphene were compared to patients who took either carbamazepine or propoxyphene and to patients who took neither of these drugs. The patients were matched for gender, age, and concomitant medications. In patients who took propoxyphene and carbamazepine the average dose of carbamazepine was lower (247.6 mg compared to 378.6 mg) and the average serum level of carbamazepine was higher (28.2 mcmol/L compared to 22.7 mcmol/L), than in those that took carbamazepine, but not propoxyphene; serum concentrations of carbamazepine metabolites were also higher. In addition, side effects related to carbamazepine occurred significantly more commonly in patients taking both carbamazepine and propoxyphene, including depression, sedation, sleep disturbances, and restlessness .
B) Seven outpatients (6 with epilepsy and 1 with trigeminal neuralgia) were receiving carbamazepine alone or in combination with phenobarbital, clonazepam, or ethosuximide . Study subjects were coadministered propoxyphene 65 mg 3 times a day. In 5 patients, carbamazepine clearance decreased 32% to 44% and carbamazepine plasma levels increased 44% to 77%. The other 2 patients discontinued the propoxyphene after 2 days due to severe side effects.
C) Six patients with epilepsy who had taken carbamazepine (600 to 800 mg/day) for more than 6 months were given dextropropoxyphene 65 mg 3 times/day . A 66% mean increase in carbamazepine serum concentrations was observed 6 days after initiation of propoxyphene dosing.
D) Three elderly patients were administered carbamazepine 200 mg 3 times a day (one patient only received 200 mg twice a day) and dextropropoxyphene 32 mg every 4 hours or 64 mg every 6 hours . All 3 developed carbamazepine toxicity and 2 became comatose.
E) A 24-year-old epileptic man on maintenance carbamazepine therapy was given dextropropoxyphene for pain due to an ear infection . He experienced acute onset ataxia, marked intention tremor, slurred speech, and multidirectional nystagmus. On presentation, he was hardly able to stand. During the preceding 24 hours, he had taken 8 coproxaml tablets (propoxyphene 32.5 mg, acetaminophen 325 mg). A fourfold increase in his carbamazepine serum concentration was found. Carbamazepine was withheld for 48 hours, by which time his serum concentration returned to normal. His symptoms rapidly resolved.
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.