Drug interactions
Isoniazid + Mavacamten
Severity: Major
Isoniazid and Mavacamten: major 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
Mavacamten is metabolized mainly by CYP2C19, and higher exposure can reduce ejection fraction and cause heart failure from systolic dysfunction. Isoniazid inhibits CYP2C19 to a moderate degree.
What this interaction means in plain words
Isoniazid and Mavacamten can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Isoniazid belongs to Anti Bacterial; Mavacamten belongs to Cardiovascular.
Why it happens
Inhibition of CYP2C19 metabolism of mavacamten, increasing exposure.
What to do
Monitor left ventricular ejection fraction and symptoms of heart failure, and adjust the mavacamten dose per echocardiographic guidance. Consider an alternative to isoniazid if feasible.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Isoniazid
Other interactions of Mavacamten
- Apalutamide + Mavacamten Contraindicated
- Carbamazepine + Mavacamten Contraindicated
- Clarithromycin + Mavacamten Contraindicated
- Dexlansoprazole + Mavacamten Contraindicated
- Efavirenz + Mavacamten Contraindicated
- Enzalutamide + Mavacamten Contraindicated
Frequently asked questions
Can I take Isoniazid with Mavacamten?
MediHelp rates the interaction as major. Isoniazid and Mavacamten can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Mavacamten is metabolized mainly by CYP2C19, and higher exposure can reduce ejection fraction and cause heart failure from systolic dysfunction. Isoniazid inhibits CYP2C19 to a moderate degree.
How serious is the interaction between Isoniazid and Mavacamten?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor left ventricular ejection fraction and symptoms of heart failure, and adjust the mavacamten dose per echocardiographic guidance. Consider an alternative to isoniazid if feasible.
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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