What the FDA labels say about taking them together
Amlodipine and diltiazem
Amlodipine's FDA label of February 15, 2023 names diltiazem in its drug interactions section; diltiazem's label does not name amlodipine itself but warns about its class (Calcium channel blockers, Calcium channel blockers (dihydropyridines)). The amlodipine label: “CYP3A inhibitors: Co-administration of a 180 mg daily dose of diltiazem with 5 mg amlodipine in elderly hypertensive patients resulted in a 60% increase in amlodipine systemic exposure.”
Check it at the source: the amlodipine FDA label on DailyMed (effective February 15, 2023, Viatris Specialty LLC); the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC).
What does the amlodipine label say about diltiazem?
Amlodipine label, drug interactionsCYP3A inhibitors: Co-administration of a 180 mg daily dose of diltiazem with 5 mg amlodipine in elderly hypertensive patients resulted in a 60% increase in amlodipine systemic exposure.
Source: FDA drug label (Norvasc), Viatris Specialty LLC, effective February 15, 2023 (SPL set 7367289c-b0b0-466a-83e2-558e2985c29f), via openFDA; the full label on DailyMed
What does the diltiazem label say about amlodipine?
Diltiazem's label does not name amlodipine itself; it warns about its class (Calcium channel blockers, Calcium channel blockers (dihydropyridines)):
Diltiazem label, drug interactionsThe depression of cardiac contractility, conductivity, and automaticity as well as the vascular dilation associated with anesthetics may be potentiated by calcium channel blockers.
Diltiazem label, drug interactionsThe depression of cardiac contractility, conductivity, and automaticity as well as the vascular dilation associated with anesthetics may be potentiated by calcium channel blockers. When used concomitantly, anesthetics and calcium channel blockers should be titrated carefully.
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
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
| Amlodipine | Diltiazem | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Heart attack and coronary artery disease | High blood pressure, Angina, Atrial fibrillation |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.0102 per tablet 5 mg tablet | $0.144 per capsule 24h ER(cd) 120 mg capsule |
| Shortage now | No current entry | A presentation being discontinued |
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