Drug interactions
Erythromycin + Mavacamten
Severity: Major
Erythromycin and Mavacamten: major interaction.
Last updated Sources: US FDA label
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
Erythromycin can raise mavacamten concentrations, which increases the risk of excessive reduction in left ventricular ejection fraction and heart failure. Mavacamten has a narrow therapeutic window guided by echocardiography.
What this interaction means in plain words
Erythromycin 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.
Erythromycin belongs to Anti Bacterial; Mavacamten belongs to Cardiovascular.
Why it happens
Inhibition of CYP3A4 (and partly CYP2C19) pathways by erythromycin lowers mavacamten clearance.
What to do
Avoid starting or stopping erythromycin without reassessing mavacamten dosing. Monitor LVEF by echocardiography and adjust the mavacamten dose per labeling.
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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References
Other interactions of Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin 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 Erythromycin with Mavacamten?
MediHelp rates the interaction as major. Erythromycin 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. Erythromycin can raise mavacamten concentrations, which increases the risk of excessive reduction in left ventricular ejection fraction and heart failure. Mavacamten has a narrow therapeutic window guided by echocardiography.
How serious is the interaction between Erythromycin 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: Avoid starting or stopping erythromycin without reassessing mavacamten dosing. Monitor LVEF by echocardiography and adjust the mavacamten dose per labeling.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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