Drug interactions
Mavacamten + Paroxetine
Severity: Major
Mavacamten and Paroxetine: 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 with a contribution from CYP3A4, and its exposure can rise with inhibitors of these enzymes. Higher mavacamten levels can reduce ejection fraction and cause heart failure. Paroxetine's inhibition of CYP2C19 is weak, but the label flags the class.
What this interaction means in plain words
Mavacamten and Paroxetine 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 belongs to Cardiovascular; Paroxetine belongs to Central Nervous System.
Why it happens
Inhibition of CYP2C19-mediated mavacamten metabolism increases mavacamten exposure.
What to do
Follow the echocardiographic and LVEF monitoring schedule in the mavacamten label when paroxetine is started or stopped. Reduce the mavacamten dose if LVEF falls or if recommended by the label.
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 Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
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 Paroxetine?
MediHelp rates the interaction as major. Mavacamten and Paroxetine 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 with a contribution from CYP3A4, and its exposure can rise with inhibitors of these enzymes. Higher mavacamten levels can reduce ejection fraction and cause heart failure. Paroxetine's inhibition of CYP2C19 is weak, but the label flags the class.
How serious is the interaction between Mavacamten and Paroxetine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Follow the echocardiographic and LVEF monitoring schedule in the mavacamten label when paroxetine is started or stopped. Reduce the mavacamten dose if LVEF falls or if recommended by the label.
What other medicines interact with Paroxetine?
MediHelp also lists interactions of Paroxetine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Paroxetine page.
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