What the FDA labels say about taking them together
Diltiazem and metoprolol
Metoprolol's FDA label of March 3, 2026 names diltiazem in its drug interactions section; diltiazem's label does not name metoprolol itself but warns about its class (Beta blockers). The metoprolol label: “Digitalis glycosides, clonidine, diltiazem, and verapamil slow atrioventricular conduction and decrease heart rate.”
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC); the metoprolol FDA label on DailyMed (effective March 3, 2026, Melinta Therapeutics, LLC).
What does the diltiazem label say about metoprolol?
Diltiazem's label does not name metoprolol itself; it warns about its class (Beta blockers):
Diltiazem label, drug interactionsBeta-blockers, digitalis, and other agents known to impair cardiac contractility and conduction may increase risk for hypotension, bradycardia, and heart failure.
Diltiazem label, drug interactionsPharmacologic studies indicate that there may be additive effects in prolonging AV conduction when using beta-blockers or digitalis concomitantly with Tiazac (see WARNINGS ).
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 metoprolol label say about diltiazem?
Metoprolol label, drug interactionsDigitalis glycosides, clonidine, diltiazem, and verapamil slow atrioventricular conduction and decrease heart rate.
Metoprolol label, warnings and precautionsWorsening cardiac failure may occur. ( 5.2 ) Bronchospastic Disease: Avoid beta-blockers. ( 5.3 ) Concomitant use of glycosides, clonidine, diltiazem and verapamil with beta-blockers can increase the risk of bradycardia.
Lopressor label (Validus Pharmaceuticals LLC, September 14, 2023), drug interactionsDRUG INTERACTIONS Catecholamine-depleting drugs may have an additive effect when given with beta-blocking agents. ( 7.1 ) Patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction. ( 7.2 ) CYP2D6 Inhibitors are likely to increase metoprolol concentration. ( 7.3 ) Concomitant use of glycosides, clonidine, and diltiazem and verapamil with beta-blockers can increase the risk of bradycardia. ( 7.4 ) Beta-blockers including metoprolol, may exacerbate the rebound hypertension that can follow the withdrawal of clonidine.
Kapspargo label (Sun Pharmaceutical Industries, Inc., April 12, 2023), warnings and precautionsConcomitant use of glycosides, clonidine, diltiazem and verapamil with beta-blockers can increase the risk of bradycardia.
Source: FDA drug label (Lopressor, NDA017963), Validus Pharmaceuticals LLC, effective September 14, 2023 (SPL set 0283bc9d-6998-493a-824a-d4c85f704111), via openFDA
Source: FDA drug label (Kapspargo, NDA210428), Sun Pharmaceutical Industries, Inc., effective April 12, 2023 (SPL set 9cfa55b4-15c6-40f7-b6e5-41096ee51bfc), via openFDA
Source: FDA drug label (TOPROL XL), Melinta Therapeutics, LLC, effective March 3, 2026 (SPL set 496ddfaa-7c9c-4888-b747-a210249b367a), 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 | Metoprolol | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | High blood pressure, Angina, Heart failure, Heart attack and coronary artery disease |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.144 per capsule 24h ER(cd) 120 mg capsule | $0.085 per tablet 100 mg tablet |
| Shortage now | A presentation being discontinued | 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