What the FDA labels say about taking them together
Phenytoin and sucralfate
Phenytoin's FDA label of October 15, 2024 names sucralfate in its drug interactions section, and sucralfate's label names phenytoin too. The sucralfate label: “… cimetidine, digoxin, fluoroquinolone antibiotics, ketoconazole, l-thyroxine, phenytoin, quinidine, ranitidine, tetracycline, and theophylline.”
Check it at the source: the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.); the sucralfate FDA label on DailyMed (effective September 2, 2026, Preferred Pharmaceuticals Inc.).
What does the phenytoin label say about sucralfate?
Phenytoin label, drug interactionsInteracting Agent: Other; Examples: Chronic alcohol abuse, diazepam, diazoxide, folic acid, reserpine, rifampin, St. John’s wort The induction potency of St. John’s wort may vary widely based on preparation., sucralfate, theophylline
Source: FDA drug label (Phenytek), Mylan Pharmaceuticals Inc., effective October 15, 2024 (SPL set 0f94c791-8b07-4b41-927e-c9f28bec5f60), via openFDA; the full label on DailyMed
What does the sucralfate label say about phenytoin?
Sucralfate label, drug interactionsDrug Interactions Some studies have shown that simultaneous sucralfate administration in healthy volunteers reduced the extent of absorption (bioavailability) of single doses of the following: cimetidine, digoxin, fluoroquinolone antibiotics, ketoconazole, l-thyroxine, phenytoin, quinidine, ranitidine, tetracycline, and theophylline.
Source: FDA drug label (Sucralfate), NDA018333 (Abbvie), as published by Preferred Pharmaceuticals Inc., effective September 2, 2026 (SPL set 536b8c00-13ab-4397-a754-63a1c92bf883), 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
| Phenytoin | Sucralfate | |
|---|---|---|
| Labeled for | Seizures and epilepsy | Acid reflux and ulcers |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.145 per capsule 100 mg capsule | $0.173 per tablet 1 g 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