What the FDA labels say about taking them together
Digoxin and sulfasalazine
Digoxin's FDA label of December 5, 2024 names sulfasalazine in its drug interactions section, and sulfasalazine's label names digoxin too. The sulfasalazine label: “Drug Interactions Reduced absorption of folic acid and digoxin have been reported when those agents were administered concomitantly with sulfasalazine.”
Check it at the source: the digoxin FDA label on DailyMed (effective December 5, 2024, Advanz Pharma (US) Corp.); the sulfasalazine FDA label on DailyMed (effective May 29, 2026, Pfizer Laboratories Div Pfizer Inc).
What does the digoxin label say about sulfasalazine?
Digoxin label, drug interactionsAcarbose, activated charcoal, albuterol, antacids, certain cancer chemotherapy or radiation therapy, cholestyramine, colestipol, extenatide, kaolin-pectin, meals high in bran, metoclopramide, miglitol, neomycin, penicillamine, phenytoin, rifampin, St. John’s Wort, sucralfate, sulfasalazine; Measure serum digoxin concentrations before initiating concomitant drugs. Continue monitoring and increase digoxin dose by approximately 20-40% as necessary.
Source: FDA drug label (Digoxin, NDA021648), Hikma Pharmaceuticals USA Inc., effective April 10, 2025 (SPL set 1b7e5c6e-e052-41b0-a4ce-05dfe62faaaf), via openFDA
Source: FDA drug label (LANOXIN), Advanz Pharma (US) Corp., effective December 5, 2024 (SPL set d91e3646-4c63-4512-ab22-db39c085c4dc), via openFDA; the full label on DailyMed
What does the sulfasalazine label say about digoxin?
Sulfasalazine label, drug interactionsDrug Interactions Reduced absorption of folic acid and digoxin have been reported when those agents were administered concomitantly with sulfasalazine.
Source: FDA drug label (Azulfidine), Pfizer Laboratories Div Pfizer Inc, effective May 29, 2026 (SPL set ddbe69f3-bd55-45f3-a64f-f60226c744c4), 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
| Digoxin | Sulfasalazine | |
|---|---|---|
| Labeled for | Heart failure, Atrial fibrillation | Crohn's disease and ulcerative colitis, Rheumatoid arthritis |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.133 per tablet 125 mcg tablet | $0.199 per tablet 500 mg tablet |
| Shortage now | No current entry | 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