Isoniazid and Levetiracetam interaction

Isoniazid and Levetiracetam: the Isoniazid prescribing label flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Isoniazid label · effective 2026-04-27

Major

To avoid phenytoin intoxication, appropriate adjustment of the anticonvulsant should be made 5,6 .

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Moderate

Carbamazepine levels should be determined prior to concurrent administration with isoniazid, signs and symptoms of carbamazepine toxicity should be monitored closely, and appropriate dosage adjustment of the anticonvulsant should be made 3 .

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.