What the FDA labels say about taking them together
Cimetidine and propranolol
Cimetidine's FDA label of July 15, 2026 names propranolol in its drug interactions section, and propranolol's label names cimetidine too. The propranolol label: “… co-administration with substrates or inhibitors of CYP2D6, such as amiodarone, cimetidine, delavudin, fluoxetine, paroxetine, quinidine, and ritonavir.”
Check it at the source: the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.); the propranolol FDA label on DailyMed (effective January 15, 2026, Mylan Pharmaceuticals Inc.).
What does the cimetidine label say about propranolol?
Cimetidine label, drug interactionsDrug Interactions Cimetidine tablets, apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs.
Source: FDA drug label (Cimetidine), Mylan Pharmaceuticals Inc., effective July 15, 2026 (SPL set 06c0a509-026f-44e0-9975-a94a8de51d43), via openFDA; the full label on DailyMed
What does the propranolol label say about cimetidine?
Propranolol label, drug interactionsSubstrates or Inhibitors of CYP2D6 Blood levels and/or toxicity of propranolol may be increased by co-administration with substrates or inhibitors of CYP2D6, such as amiodarone, cimetidine, delavudin, fluoxetine, paroxetine, quinidine, and ritonavir.
Source: FDA drug label (Propranolol Hydrochloride), Mylan Pharmaceuticals Inc., effective January 15, 2026 (SPL set b94dcec7-7633-4a33-9cea-48161adeaf93), 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
| Cimetidine | Propranolol | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | High blood pressure, Angina, Atrial fibrillation, Migraine |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.236 per tablet 300 mg tablet | $0.0493 per tablet 20 mg tablet |
| Shortage now | No current entry | In shortage |
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