Drug interactions
Disulfiram + Isoniazid
Severity: Moderate
Disulfiram and Isoniazid: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Combined use has been associated with neurological and behavioral effects such as ataxia, irritability, altered mood and incoordination. Both drugs can also cause peripheral neuropathy and hepatotoxicity, so the combination adds to these risks.
What this interaction means in plain words
Disulfiram and Isoniazid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Probable pharmacodynamic CNS toxicity, possibly with altered isoniazid and disulfiram metabolism; the exact mechanism is not firmly established.
What to do
Monitor mental status, gait, neuropathy symptoms and liver enzymes. Stop disulfiram or review the regimen if CNS symptoms appear.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Isoniazid
Frequently asked questions
Can I take Disulfiram with Isoniazid?
MediHelp rates the interaction as moderate. Disulfiram and Isoniazid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Combined use has been associated with neurological and behavioral effects such as ataxia, irritability, altered mood and incoordination. Both drugs can also cause peripheral neuropathy and hepatotoxicity, so the combination adds to these risks.
How serious is the interaction between Disulfiram and Isoniazid?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor mental status, gait, neuropathy symptoms and liver enzymes. Stop disulfiram or review the regimen if CNS symptoms appear.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
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