By Kayla Hyland, DVM; Rania Gollakner, BS, DVM, MPH

What is carbamazepine?

Carbamazepine (brand names: Tegretol®, Carbatrol®, Equetro®, Mazepine®) is an anti-seizure and pain medication that is used to treat seizures and chronic pain, primarily nerve pain. It is also used to treat behavior disorders such as aggression, and in horses, is used to treat photic head shaking. Its use in veterinary medicine is uncommon currently.

Its use in dogs, cats, and horses to treat seizures, pain, and behavior problems is “off label” or “extra label”. Many drugs are commonly prescribed for off-label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How is carbamazepine given?

Carbamazepine is given by mouth in the form of a tablet or liquid. Measure liquid doses carefully. It may be given with or without food, but if your pet vomits after dosing on an empty stomach, give future doses with food or a treat. If you are pregnant, wear gloves, handle carefully, and wash hands after dosing, as this medication may cause birth defects; do not crush or split tablets to avoid inhaling the dust.

This medication should take effect within 1 to 2 hours; however, effects may not be noticeable and therefore laboratory tests may need to be done to evaluate this medication’s efficacy.

What if I miss giving my pet the medication?

If you miss a dose, give it when you remember; however, if it is close to time for the next dose, skip the dose you missed, give it at the next scheduled time, and return to the regular dosing schedule. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

Studies in animals are lacking, but in humans, this medication may cause dizziness, sleepiness, nausea, and vomiting. Serious side effects in humans include abnormal heart rhythms, heart failure, bone marrow suppression (low energy, bleeding, bruising, fever), skin syndromes (rashes, redness, or sores), or liver toxicity (yellowing of the skin, eyes, or gums).

This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

Do not use in pets that have recently used flea or tick products with amitraz. Use cautiously in patients with heart rhythm disorders. Studies in animals are lacking, but in humans, this medication should not be used in patients that are allergic to it or patients with bone marrow disease, those who have recently taken MAOIs, or those that are pregnant. In humans, it should be used cautiously in patients with significant liver disease or patients that are lactating. These considerations should be carried over to veterinary patients.

Are there any drug interactions I should be aware of?

Studies in animals are lacking; however, many medications in humans should be used with caution when given with carbamazepine, including some vitamins.

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

Is there any monitoring that needs to be done with this medication?

Complete blood counts and liver function tests should be monitored occasionally. Your veterinarian may monitor your pet to be sure that the medication is working.

How do I store carbamazepine?

Store this medication at room temperature below 30°C (86°F) in a tight container protected from moisture and light.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.

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