What the FDA labels say about taking them together
Cholestyramine and propranolol
Cholestyramine's FDA label of August 20, 2026 names propranolol in its drug interactions section, and propranolol's label names cholestyramine too. The propranolol label: “Lipid Lowering Drugs Co-administration of cholestyramine or colestipol with propranolol resulted in up to 50% decrease in propranolol concentrations.”
Check it at the source: the cholestyramine FDA label on DailyMed (effective August 20, 2026, AiPing Pharmaceutical, Inc.); the propranolol FDA label on DailyMed (effective January 15, 2026, Mylan Pharmaceuticals Inc.).
What does the cholestyramine label say about propranolol?
Cholestyramine label, drug interactionsDrug Interactions Cholestyramine resin may delay or reduce the absorption of concomitant oral medication such as phenylbutazone, warfarin, thiazide diuretics (acidic) or propranolol (basic), as well as tetracycline, penicillin G, phenobarbital, thyroid and thyroxine preparations, estrogens and progestins and digitalis.
Source: FDA drug label (Cholestyramine), AiPing Pharmaceutical, Inc., effective August 20, 2026 (SPL set 214ea05f-de81-4026-9df9-4ce3820668ee), via openFDA; the full label on DailyMed
What does the propranolol label say about cholestyramine?
Propranolol label, drug interactionsLipid Lowering Drugs Co-administration of cholestyramine or colestipol with propranolol resulted in up to 50% decrease in propranolol concentrations.
Inderal Xl label (ANI Pharmaceuticals, Inc., August 27, 2026), drug interactionsCholestyramine and Colestipol: Co-administered cholestyramine or colestipol significantly reduces the plasma concentrations of co-administered propranolol which may result in loss of efficacy [see Clinical Pharmacology ( 12.7 )].
Source: FDA drug label (Inderal Xl, NDA021438), ANI Pharmaceuticals, Inc., effective August 27, 2026 (SPL set ac196ff5-9215-402b-bc57-69aa87f8bade), via openFDA
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
| Cholestyramine | Propranolol | |
|---|---|---|
| Labeled for | High cholesterol | High blood pressure, Angina, Atrial fibrillation, Migraine |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.834 per packet Cholestyramine packet | $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