Drug interactions
Mavacamten + Orphenadrin
Severity: Moderate
Mavacamten and Orphenadrin: 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
Mavacamten is metabolized mainly by CYP2C19 with CYP3A4 contribution, and higher exposure can reduce ejection fraction and cause heart failure. Orphenadrine is a possible weak enzyme inhibitor, so exposure may rise, although the effect is uncertain.
What this interaction means in plain words
Mavacamten and Orphenadrin 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.
Mavacamten belongs to Cardiovascular; Orphenadrin belongs to Musculoskeletal.
Why it happens
Possible weak inhibition of CYP2C19/CYP3A4 metabolism of mavacamten.
What to do
Monitor left ventricular ejection fraction and clinical status when orphenadrine is started or stopped. Adjust mavacamten dose per echocardiographic guidance.
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 Orphenadrin
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 Mavacamten with Orphenadrin?
MediHelp rates the interaction as moderate. Mavacamten and Orphenadrin 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. Mavacamten is metabolized mainly by CYP2C19 with CYP3A4 contribution, and higher exposure can reduce ejection fraction and cause heart failure. Orphenadrine is a possible weak enzyme inhibitor, so exposure may rise, although the effect is uncertain.
How serious is the interaction between Mavacamten and Orphenadrin?
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 left ventricular ejection fraction and clinical status when orphenadrine is started or stopped. Adjust mavacamten dose per echocardiographic guidance.
What other medicines interact with Orphenadrin?
MediHelp also lists interactions of Orphenadrin with, for example, Alfentanil, Amobarbital, Benzhydrocodone / acetaminophen. The full list is on the Orphenadrin page.
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