Drug interactions
Isoniazid + Pyrazinamide
Severity: Moderate
Isoniazid and Pyrazinamide: 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
Both drugs are hepatotoxic, and used together in standard tuberculosis regimens they add to the risk of drug-induced liver injury. The combination is nevertheless routinely used because of its therapeutic value.
What this interaction means in plain words
Isoniazid and Pyrazinamide 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.
Isoniazid belongs to Anti Bacterial; Pyrazinamide belongs to Anti Bacterial.
Why it happens
Additive hepatotoxicity through separate hepatocellular injury pathways.
What to do
Check baseline liver enzymes and repeat them periodically during treatment, especially in patients with liver disease, alcohol use or older age. Interrupt therapy if transaminases rise markedly or symptoms of hepatitis 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
Other interactions of Pyrazinamide
- Pexidartinib + Pyrazinamide Major
- Pretomanid + Pyrazinamide Major
- Cyclosporine + Pyrazinamide Moderate
- Mipomersen + Pyrazinamide Moderate
- Probenecid + Pyrazinamide Moderate
- Pyrazinamide + Rifampin Moderate
Frequently asked questions
Can I take Isoniazid with Pyrazinamide?
MediHelp rates the interaction as moderate. Isoniazid and Pyrazinamide 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. Both drugs are hepatotoxic, and used together in standard tuberculosis regimens they add to the risk of drug-induced liver injury. The combination is nevertheless routinely used because of its therapeutic value.
How serious is the interaction between Isoniazid and Pyrazinamide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check baseline liver enzymes and repeat them periodically during treatment, especially in patients with liver disease, alcohol use or older age. Interrupt therapy if transaminases rise markedly or symptoms of hepatitis 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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