What the FDA labels say about taking them together
Cimetidine and dalfampridine
Dalfampridine's FDA label of January 16, 2026 names cimetidine in its drug interactions section; the cimetidine label PlainMeds reads does not name dalfampridine. The dalfampridine label: “Concurrent treatment with OCT2 inhibitors, such as cimetidine, may cause increased exposure to dalfampridine [ see Clinical Pharmacology ].”
Check it at the source: the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.); the dalfampridine FDA label on DailyMed (effective January 16, 2026, Merz Pharmaceuticals, LLC).
What does the cimetidine label say about dalfampridine?
Cimetidine's label (effective July 15, 2026) does not name dalfampridine in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Cimetidine), Mylan Pharmaceuticals Inc., effective July 15, 2026 (SPL set 06c0a509-026f-44e0-9975-a94a8de51d43), via openFDA; the full label on DailyMed
What does the dalfampridine label say about cimetidine?
Dalfampridine label, drug interactionsConcurrent treatment with OCT2 inhibitors, such as cimetidine, may cause increased exposure to dalfampridine [ see Clinical Pharmacology (12.3) ].
Source: FDA drug label (AMPYRA), Merz Pharmaceuticals, LLC, effective January 16, 2026 (SPL set 550eb76a-e4a6-4fa1-ad65-c0fd8b0ce783), 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
| Cimetidine | Dalfampridine | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | Multiple sclerosis |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.236 per tablet 300 mg tablet | $0.399 per tablet 10 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