What the FDA labels say about taking them together
Chlorothiazide and cholestyramine
Chlorothiazide's FDA label (Diuril) of November 1, 2021 names cholestyramine in its drug interactions section; cholestyramine's label does not name chlorothiazide itself but warns about its class (Thiazide diuretics).
Check it at the source: the chlorothiazide FDA label on DailyMed (effective August 4, 2026, Sagent Pharmaceuticals); the cholestyramine FDA label on DailyMed (effective August 20, 2026, AiPing Pharmaceutical, Inc.).
What does the chlorothiazide label say about cholestyramine?
Diuril label (Salix Pharmaceuticals, Inc, November 1, 2021), drug interactionsCholestyramine and Colestipol Resins - Both cholestyramine and colestipol resins have the potential of binding thiazide diuretics and reducing diuretic absorption from the gastrointestinal tract.
Source: FDA drug label (Diuril, NDA011870), Salix Pharmaceuticals, Inc, effective November 1, 2021 (SPL set bd936e35-1af8-42da-bcc0-f22489d68574), via openFDA
Source: FDA drug label (chlorothiazide sodium), Sagent Pharmaceuticals, effective August 4, 2026 (SPL set 82dd0bdd-e6bd-48ea-8f58-c8bf71bbfe2c), via openFDA; the full label on DailyMed
What does the cholestyramine label say about chlorothiazide?
Cholestyramine's label does not name chlorothiazide itself; it warns about its class (Thiazide diuretics):
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
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
| Chlorothiazide | Cholestyramine | |
|---|---|---|
| Labeled for | Heart failure, Edema (fluid retention), High blood pressure | High cholesterol |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.834 per packet Cholestyramine packet |
| Shortage now | A presentation being discontinued | No current entry |
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