Two medicines, side by side
Amlodipine vs diltiazem
Amlodipine and diltiazem are both labeled for high blood pressure and angina. Drugs@FDA records approvals of amlodipine since 1992 and of diltiazem since 1982. Pharmacies paid $0.0102 per amlodipine besylate 5 mg tablet and $0.144 per diltiazem 24h ER(cd) 120 mg capsule (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. How each works, in its label's words: Amlodipine, “Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow‑channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac …”; Diltiazem, “Mechanisms of Action Hypertension: Diltiazem produces its antihypertensive effect primarily by relaxation of vascular smooth muscle and the resultant decrease in peripheral vascular resistance.”
Check it at the source: the amlodipine FDA label on DailyMed (effective February 15, 2023); the diltiazem FDA label on DailyMed (effective August 7, 2026).
Highlights of the amlodipine record
Amlodipine (Norvasc) · label of February 15, 2023
Used for
From the label: indicationsNORVASC is a calcium channel blocker and may be used alone or in combination with other antihypertensive and antianginal agents for the treatment of: • Hypertension ( 1.1 ) o NORVASC is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. […]
On the market
- Earliest approval on file
- July 31, 1992
- Generic labelers
- 42 labelers
- Pharmacy cost
- $0.0102 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 30
Highlights of the diltiazem record
Diltiazem (Cardizem) · label of August 7, 2026
Used for
From the label: indicationsHypertension Tiazac is indicated for the treatment of hypertension. It may be used alone or in combination with other antihypertensive medications. Chronic Stable Angina Tiazac is indicated for the treatment of chronic stable angina.
On the market
- Earliest approval on file
- November 5, 1982
- Generic labelers
- 50 labelers
- Pharmacy cost
- $0.144 per capsule
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 29
Source: FDA drug labels via openFDA (Amlodipine label of February 15, 2023, Diltiazem label of August 7, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do amlodipine and diltiazem differ on the record?
How each works, in its label's words: Amlodipine, “Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow‑channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac …”; Diltiazem, “Mechanisms of Action Hypertension: Diltiazem produces its antihypertensive effect primarily by relaxation of vascular smooth muscle and the resultant decrease in peripheral vascular resistance.”
Both are in FDA's class calcium channel blockers.
Generics: amlodipine since 2005; diltiazem since 1992 (Drugs@FDA).
| Amlodipine | Diltiazem | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Heart attack and coronary artery disease | High blood pressure, Angina, Atrial fibrillation |
| Pharmacologic class | Calcium Channel Blocker, Dihydropyridine Calcium Channel Blocker | Calcium Channel Blocker |
| How it works (label) | Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow‑channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. | Mechanisms of Action Hypertension: Diltiazem produces its antihypertensive effect primarily by relaxation of vascular smooth muscle and the resultant decrease in peripheral vascular resistance. |
| Half-life (label) | n/a | The plasma elimination half-life of diltiazem is approximately 3.0 to 4.5 hours. |
| Earliest approval on file (Drugs@FDA) | July 31, 1992 | November 5, 1982 |
| First generic approved | October 3, 2005 | November 5, 1992 |
| Generic labelers (NDC) | 42 labelers | 50 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0102 per tablet (Amlodipine besylate 5 mg tablet) | $0.144 per capsule (Diltiazem 24h ER(cd) 120 mg capsule) |
| 12-month price change | -10% | -4% |
| Boxed warning | No | No |
| Shortage now | No current entry | A presentation being discontinued |
| Recalls recorded | 30 | 29 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 409,186 | 34,213 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
Do their labels mention each other?
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 labels via openFDA
What next?
- Alternatives to amlodipine
- every medicine labeled for the same conditions