Two medicines, side by side
Diltiazem vs verapamil
Diltiazem and verapamil are both labeled for high blood pressure, atrial fibrillation and angina. Drugs@FDA records approvals of diltiazem since 1982 and of verapamil since 1981. Pharmacies paid $0.144 per diltiazem 24h ER(cd) 120 mg capsule and $0.191 per verapamil ER 180 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. How each works, in its label's words: 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.”; Verapamil, “Mechanism of action Essential hypertension: Verapamil exerts antihypertensive effects by decreasing systemic vascular resistance, usually without orthostatic decreases in blood pressure or reflex …”
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026); the verapamil FDA label on DailyMed (effective April 6, 2026).
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
Highlights of the verapamil record
Verapamil (Isoptin) · label of April 6, 2026
Used for
From the label: indicationsVerapamil hydrochloride extended-release tablets are 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. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including this drug. […]
On the market
- Earliest approval on file
- August 12, 1981
- Generic labelers
- 43 labelers
- Pharmacy cost
- $0.191 per tablet
Supply and safety
- Shortage
- A presentation being discontinued
- Recalls
- 7
Source: FDA drug labels via openFDA (Diltiazem label of August 7, 2026, Verapamil label of April 6, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do diltiazem and verapamil differ on the record?
How each works, in its label's words: 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.”; Verapamil, “Mechanism of action Essential hypertension: Verapamil exerts antihypertensive effects by decreasing systemic vascular resistance, usually without orthostatic decreases in blood pressure or reflex …”
Both are in FDA's class calcium channel blockers.
Half-life, in each label's words: Diltiazem, “The plasma elimination half-life of diltiazem is approximately 3.0 to 4.5 hours.”; Verapamil, “The mean elimination half-life in single-dose studies ranged from 2.8 to 7.4 hours.”
Generics: diltiazem since 1992; verapamil since 1985 (Drugs@FDA).
| Diltiazem | Verapamil | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | High blood pressure, Atrial fibrillation, Angina |
| Pharmacologic class | Calcium Channel Blocker | Calcium Channel Blocker |
| How it works (label) | Mechanisms of Action Hypertension: Diltiazem produces its antihypertensive effect primarily by relaxation of vascular smooth muscle and the resultant decrease in peripheral vascular resistance. | Mechanism of action Essential hypertension: Verapamil exerts antihypertensive effects by decreasing systemic vascular resistance, usually without orthostatic decreases in blood pressure or reflex tachycardia; … |
| Half-life (label) | The plasma elimination half-life of diltiazem is approximately 3.0 to 4.5 hours. | The mean elimination half-life in single-dose studies ranged from 2.8 to 7.4 hours. |
| Earliest approval on file (Drugs@FDA) | November 5, 1982 | August 12, 1981 |
| First generic approved | November 5, 1992 | November 12, 1985 |
| Generic labelers (NDC) | 50 labelers | 43 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.144 per capsule (Diltiazem 24h ER(cd) 120 mg capsule) | $0.191 per tablet (Verapamil ER 180 mg tablet) |
| 12-month price change | -4% | +7% |
| Boxed warning | No | No |
| Shortage now | A presentation being discontinued | A presentation being discontinued |
| Recalls recorded | 29 | 7 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 34,213 | 4,242 |
| 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)
What next?
- Alternatives to diltiazem
- every medicine labeled for the same conditions