What the FDA labels say about taking them together
Cholestyramine and spironolactone
Spironolactone's FDA label of November 28, 2025 names cholestyramine in its drug interactions section; the cholestyramine label PlainMeds reads does not name spironolactone. The spironolactone label: “Spironolactone oral suspension can interfere with radioimmunologic assays of digoxin exposure Cholestyramine:”
Check it at the source: the cholestyramine FDA label on DailyMed (effective August 20, 2026, AiPing Pharmaceutical, Inc.); the spironolactone FDA label on DailyMed (effective November 28, 2025, Pfizer Laboratories Div Pfizer Inc).
What does the cholestyramine label say about spironolactone?
Cholestyramine's label (effective August 20, 2026) does not name spironolactone in these sections. A label lists what its studies and reports found; it is not a complete list.
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 spironolactone label say about cholestyramine?
Spironolactone label, drug interactionsCholestyramine: Hyperkalemic metabolic acidosis has been reported with concomitant use ( 7.5 ).
Spironolactone label (Atlantic Biologicals Corp., August 28, 2026), drug interactionsSpironolactone oral suspension can interfere with radioimmunologic assays of digoxin exposure ( 7.4 ) Cholestyramine:
Source: FDA drug label (Spironolactone, NDA209478), Atlantic Biologicals Corp., effective August 28, 2026 (SPL set 5a203ae4-0ed1-0099-e063-6294a90abc85), via openFDA
Source: FDA drug label (Aldactone), Pfizer Laboratories Div Pfizer Inc, effective November 28, 2025 (SPL set 0fed2822-3a03-4b64-9857-c682fcd462bc), 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 | Spironolactone | |
|---|---|---|
| Labeled for | High cholesterol | Heart failure, Edema (fluid retention), High blood pressure |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.834 per packet Cholestyramine packet | $0.0426 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