Esomeprazole and Mavacamten: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Mavacamten
Esomeprazole
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased mavacamten exposure, an increased risk of mavacamten-related adverse reactions, reduced esomeprazole exposure and reduced efficacy of esomeprazole
Interaction Deep Dive
Coadministration mavacamten and esomeprazole (moderate CYP2C19 inhibitor and CYP2C19 substrate) may increase mavacamten exposure, which may increase mavacamten-related adverse reactions. Closely monitor as it may also reduce esomeprazole exposure which may reduce efficacy of esomeprazole. In patients who are on stable therapy with esomeprazole, initiate mavacamten at 2.5 mg orally once daily. Interrupt mavacamten if Valsalva LVOT gradient is less than 20 mm Hg at week 4 or 8. Treatment may be resumed after 4 weeks at 2.5 mg once daily if LVEF is more than or equal to 50%. If treatment is resumed at week 12, recheck clinical status, Valsalva LVOT gradient and LVEF in 4 weeks, and maintain the current dose for the next 8 weeks unless LVEF is less than 50%. Reduce dose of mavacamten to the next lower daily (mg) dose level in patients who are on mavacamten and intend to initiate esomeprazole. Perform clinical and ECG assessment 4 weeks after inhibitor initiation, and do not up-titrate to the next higher (mg) dose level of mavacamten until 12 weeks after inhibitor. Avoid esomeprazole initiation in patients who are on stable treatment with 2.5 mg of mavacamten because a lower dose is not available. An increase in dose of mavacamten may be needed if esomeprazole is discontinued after long-term concomitant use. Monitor for new or worsening symptoms. For short-term use, interrupt mavacamten for the duration of treatment with esomeprazole. Mavacamten may be reinitiated at the previous dose immediately on discontinuation of concomitant therapy1.
Why it happens (mechanism)
Inhibition of CYP2C19-mediated metabolism of mavacamten; induction of CYP2C19-mediated metabolism of esomeprazole
Literature reports
2 reports — tap to read
a) In a drug interaction study, concomitant use of mavacamten 15 mg with omeprazole 20 mg once daily increased mavacamten AUC(inf) by 48% with no effect on Cmax in healthy CYP2C19 normal and rapid metabolizers 1.
b) In a drug interaction study concomitant use of mavacamten once daily in hypertrophic cardiomyopathy patients is predicted to decrease AUC and Cmax of omeprazole, a CYP2C19 substrate, by 48% and by 17%, respectively, depending on the dose of mavacamten and CYP2C19 phenotype 1.
Common questions
Can I take Esomeprazole and Mavacamten together?
Increased mavacamten exposure, an increased risk of mavacamten-related adverse reactions, reduced esomeprazole exposure and reduced efficacy of esomeprazole Always confirm with your pharmacist or prescriber before making any change.
How serious is the Esomeprazole and Mavacamten interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Esomeprazole or Mavacamten need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: CAMZYOS(R) oral capsules, mavacamten oral capsules. Bristol-Myers Squibb Company (per Manufacturer), Princeton, NJ, 2025. DailyMed
Keep reading about Mavacamten
Keep reading about Esomeprazole
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