What the FDA labels say about taking them together
Cholestyramine and hydrochlorothiazide
Hydrochlorothiazide's FDA label (Hydrochlorothiazide) of December 5, 2025 names cholestyramine in its drug interactions section; cholestyramine's label does not name hydrochlorothiazide itself but warns about its class (Thiazide diuretics). The hydrochlorothiazide label: “Cholestyramine and colestipol: Reduced absorption of thiazides Lithium: Increased lithium concentrations and lithium toxicity Antidiabetic drugs:”
Check it at the source: the cholestyramine FDA label on DailyMed (effective August 20, 2026, AiPing Pharmaceutical, Inc.); the hydrochlorothiazide FDA label on DailyMed (effective June 12, 2026, Leading Pharma, LLC).
What does the cholestyramine label say about hydrochlorothiazide?
Cholestyramine's label does not name hydrochlorothiazide 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
What does the hydrochlorothiazide label say about cholestyramine?
Hydrochlorothiazide label (QPharma, Inc., December 5, 2025), drug interactionsCholestyramine and colestipol resins - Cholestyramine and colestipol resins bind the hydrochlorothiazide and reduce its absorption from the gastrointestinal tract by up to 85 and 43 percent, respectively.
Inzirqo label (ANI Pharmaceuticals, Inc., December 16, 2025), drug interactionsCholestyramine and colestipol: Reduced absorption of thiazides (7.1) Lithium: Increased lithium concentrations and lithium toxicity (7.2) Antidiabetic drugs:
Source: FDA drug label (Hydrochlorothiazide, NDA020504), QPharma, Inc., effective December 5, 2025 (SPL set 5bacc909-6b02-4815-85ef-55fd25b1b1f7), via openFDA
Source: FDA drug label (Inzirqo, NDA219141), ANI Pharmaceuticals, Inc., effective December 16, 2025 (SPL set 41aaea48-6c1b-42c8-a96f-5923d49dc934), via openFDA
Source: FDA drug label (HYDROCHLOROTHIAZIDE), Leading Pharma, LLC, effective June 12, 2026 (SPL set 8c868894-667e-4a51-906a-838d63e420ba), 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 | Hydrochlorothiazide | |
|---|---|---|
| Labeled for | High cholesterol | Heart failure, High blood pressure, Edema (fluid retention) |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.834 per packet Cholestyramine packet | $0.0115 per tablet 25 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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