Carbamazepine/Selected Barbiturates Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Your barbiturate may speed up how quickly your body processes carbamazepine.

What might happen:

Your blood levels of carbamazepine could decrease, which may increase your risk of seizures.

What you should do about this interaction:

Let your healthcare professional (e.g. doctor or pharmacist) know that you are taking these medicines together. If you notice decreased effectiveness of your medicine (e.g. increase in seizures), contact your doctor. Your doctor may check medicine blood levels and may need to adjust the dose of your medicine.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

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  • 8.Spina E, Martines C, Fazio A, Trio R, Pisani F, Tomson T. Effect of phenobarbital on the pharmacokinetics of carbamazepine-10,11-epoxide, an active metabolite of carbamazepine. Ther Drug Monit 1991 Mar;13(2):109-12.
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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.