What the FDA labels say about taking them together
Aspirin/dipyridamole and phenytoin
Aspirin/dipyridamole's FDA label of January 5, 2026 names phenytoin in its drug interactions section; the phenytoin labels PlainMeds reads (2) do not name aspirin/dipyridamole. The aspirin/dipyridamole label: “Anticonvulsants Salicylic acid can displace protein-bound phenytoin and valproic acid, leading to a decrease in the total concentration of phenytoin and an increase in serum valproic acid levels.”
Check it at the source: the aspirin/dipyridamole FDA label on DailyMed (effective January 5, 2026, Glenmark Pharmaceuticals Inc., USA); the phenytoin FDA label on DailyMed (effective October 15, 2024, Mylan Pharmaceuticals Inc.).
What does the aspirin/dipyridamole label say about phenytoin?
Aspirin/dipyridamole label, drug interactionsAnticonvulsants Salicylic acid can displace protein-bound phenytoin and valproic acid, leading to a decrease in the total concentration of phenytoin and an increase in serum valproic acid levels.
Source: FDA drug label (ASPRIN AND EXTENDED-RELEASE DIPYRIDAMOLE), Glenmark Pharmaceuticals Inc., USA, effective January 5, 2026 (SPL set 467d6ce3-bc05-4aa1-87cc-3214fd628d39), via openFDA; the full label on DailyMed
What does the phenytoin label say about aspirin/dipyridamole?
Phenytoin's label (effective October 15, 2024) and its 1 other brand-application label do not name aspirin/dipyridamole in these sections. A label lists what its studies and reports found; it is not a complete list.
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
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
| Aspirin/dipyridamole | Phenytoin | |
|---|---|---|
| Labeled for | Stroke prevention | Seizures and epilepsy |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.559 per unit 25-200 mg | $0.145 per capsule 100 mg capsule |
| 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