Drug interactions
Isoniazid + Ranolazine
Severity: Moderate
Isoniazid and Ranolazine: 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
Ranolazine is a CYP3A4 substrate that prolongs the QT interval in a dose-related manner. Isoniazid may increase its levels, giving more dizziness, nausea and QT effect.
What this interaction means in plain words
Isoniazid and Ranolazine 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; Ranolazine belongs to Cardiovascular.
Why it happens
Isoniazid inhibits CYP3A4, reducing ranolazine metabolism.
What to do
Monitor for adverse effects and the QTc, and limit the ranolazine dose if tolerability is poor.
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 Ranolazine
- Adagrasib + Ranolazine Contraindicated
- Amobarbital + Ranolazine Contraindicated
- Apalutamide + Ranolazine Contraindicated
- Butabarbital + Ranolazine Contraindicated
- Carbamazepine + Ranolazine Contraindicated
- Clarithromycin + Ranolazine Contraindicated
Frequently asked questions
Can I take Isoniazid with Ranolazine?
MediHelp rates the interaction as moderate. Isoniazid and Ranolazine 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. Ranolazine is a CYP3A4 substrate that prolongs the QT interval in a dose-related manner. Isoniazid may increase its levels, giving more dizziness, nausea and QT effect.
How serious is the interaction between Isoniazid and Ranolazine?
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 for adverse effects and the QTc, and limit the ranolazine dose if tolerability is poor.
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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