What the FDA labels say about taking them together
Diltiazem and mavacamten
Mavacamten's FDA label of April 17, 2025 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name mavacamten. The mavacamten label: “Avoid concomitant use of CAMZYOS in patients on disopyramide, ranolazine, verapamil with a beta blocker, or diltiazem with a beta blocker as these medications and combinations increase the risk of left ventricular …”
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC); the mavacamten FDA label on DailyMed (effective April 17, 2025, Myokardia, Inc.).
What does the diltiazem label say about mavacamten?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels do not name mavacamten in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (TIAZAC EXTENDED RELEASE), Bausch Health US, LLC, effective August 7, 2026 (SPL set c567fe7e-887e-4291-a0d1-2dd3f25cbf25), via openFDA; the full label on DailyMed
What does the mavacamten label say about diltiazem?
Mavacamten label, drug interactionsAvoid concomitant use of CAMZYOS in patients on disopyramide, ranolazine, verapamil with a beta blocker, or diltiazem with a beta blocker as these medications and combinations increase the risk of left ventricular systolic dysfunction and heart failure symptoms and clinical experience is limited [see Warnings and Precautions (5.1) ].
Source: FDA drug label (CAMZYOS), NDA214998 (Bristol), as published by Myokardia, Inc., effective April 17, 2025 (SPL set 669c936b-3ee6-4e36-8a22-79dd11b1255b), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Diltiazem | Mavacamten | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | n/a |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.144 per capsule 24h ER(cd) 120 mg capsule | n/a |
| Shortage now | A presentation being discontinued | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once