What the FDA labels say about taking them together
Diltiazem and siponimod
Siponimod's FDA label of June 30, 2026 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name siponimod. The siponimod label: “Experience with MAYZENT is limited in patients receiving concurrent therapy with drugs that decrease heart rate.”
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC); the siponimod FDA label on DailyMed (effective June 30, 2026, Novartis Pharmaceuticals Corporation).
What does the diltiazem label say about siponimod?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels do not name siponimod 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 siponimod label say about diltiazem?
Siponimod label, drug interactionsBecause of the potential additive effects on heart rate, treatment with MAYZENT should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties, heart-rate lowering calcium channel blockers (e.g., verapamil, diltiazem), or other drugs that may decrease heart rate (e.g., ivabradine, digoxin) [see Warnings and Precautions (5.4) and Drug Interactions (7.3)].
Siponimod label, warnings and precautionsExperience with MAYZENT is limited in patients receiving concurrent therapy with drugs that decrease heart rate (e.g., beta-blockers, calcium channel blockers - diltiazem and verapamil, and other drugs that may decrease heart rate, such as ivabradine and digoxin).
Source: FDA drug label (MAYZENT), Novartis Pharmaceuticals Corporation, effective June 30, 2026 (SPL set 44492772-5aed-4627-bd85-e8e89f308bb3), 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 | Siponimod | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | Multiple sclerosis |
| Boxed warning | No | No |
| 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