Two medicines, side by side
Diltiazem vs propranolol
Diltiazem and propranolol are both labeled for high blood pressure, atrial fibrillation and angina. Drugs@FDA records approvals of diltiazem since 1982 and of propranolol since 1967. Pharmacies paid $0.144 per diltiazem 24h ER(cd) 120 mg capsule and $0.0493 per propranolol 20 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, diltiazem is a calcium channel blocker and propranolol a beta-adrenergic blocker.
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026); the propranolol FDA label on DailyMed (effective January 15, 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 propranolol record
Propranolol (Inderal) · label of January 15, 2026
Used for
From the label: indicationsHypertension Propranolol hydrochloride tablets are indicated in the management of hypertension. It may be used alone or used in combination with other antihypertensive agents, particularly a thiazide diuretic. Propranolol hydrochloride tablets are not indicated in the management of hypertensive emergencies. […]
On the market
- Earliest approval on file
- November 13, 1967
- Generic labelers
- 42 labelers
- Pharmacy cost
- $0.0493 per tablet
Supply and safety
- Shortage
- In shortage
- Recalls
- 4
Source: FDA drug labels via openFDA (Diltiazem label of August 7, 2026, Propranolol label of January 15, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do diltiazem and propranolol differ on the record?
In FDA's classes, diltiazem is a calcium channel blocker and propranolol a beta-adrenergic blocker.
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.”; Propranolol, “Mechanism of Action The mechanism of the antihypertensive effect of propranolol has not been established.”
Half-life, in each label's words: Diltiazem, “The plasma elimination half-life of diltiazem is approximately 3.0 to 4.5 hours.”; Propranolol, “The plasma half-life of propranolol is from 3 to 6 hours.”
Generics: diltiazem since 1992; propranolol since 1985 (Drugs@FDA).
| Diltiazem | Propranolol | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | High blood pressure, Angina, Atrial fibrillation, Migraine |
| Pharmacologic class | Calcium Channel Blocker | beta-Adrenergic 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 The mechanism of the antihypertensive effect of propranolol has not been established. |
| Half-life (label) | The plasma elimination half-life of diltiazem is approximately 3.0 to 4.5 hours. | The plasma half-life of propranolol is from 3 to 6 hours. |
| Earliest approval on file (Drugs@FDA) | November 5, 1982 | November 13, 1967 |
| First generic approved | November 5, 1992 | July 30, 1985 |
| Generic labelers (NDC) | 50 labelers | 42 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.144 per capsule (Diltiazem 24h ER(cd) 120 mg capsule) | $0.0493 per tablet (Propranolol 20 mg tablet) |
| 12-month price change | -4% | -17% |
| Boxed warning | No | No |
| Shortage now | A presentation being discontinued | In shortage |
| Recalls recorded | 29 | 4 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 34,213 | 71,660 |
| 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?
Diltiazem label, drug interactionsAdministration of diltiazem hydrochloride concomitantly with propranolol in five normal volunteers resulted in increased propranolol levels in all subjects and bioavailability of propranolol was increased approximately 50%.
Diltiazem label, drug interactionsAdministration of CARDIZEM (diltiazem hydrochloride) concomitantly with propranolol in five normal volunteers resulted in increased propranolol levels in all subjects, and bioavailability of propranolol was increased approximately 50%.
Propranolol label, drug interactionsCo-administration of propranolol and diltiazem in patients with cardiac disease has been associated with bradycardia, hypotension, high-degree heart block, and heart failure.
Source: FDA drug labels via openFDA
What next?
- Alternatives to diltiazem
- every medicine labeled for the same conditions