What the FDA labels say about taking them together
Cimetidine and valproic acid
Valproic acid's FDA label of January 24, 2025 names cimetidine in its drug interactions section; the cimetidine label PlainMeds reads does not name valproic acid. The valproic acid label: “Cimetidine and Ranitidine Cimetidine and ranitidine do not affect the clearance of valproate.”
Check it at the source: the cimetidine FDA label on DailyMed (effective July 15, 2026, Mylan Pharmaceuticals Inc.); the valproic acid FDA label on DailyMed (effective January 24, 2025, PAI Holdings, LLC dba PAI Pharma).
What does the cimetidine label say about valproic acid?
Cimetidine's label (effective July 15, 2026) does not name valproic acid 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 valproic acid label say about cimetidine?
Valproic acid label, drug interactionsCimetidine and Ranitidine Cimetidine and ranitidine do not affect the clearance of valproate.
Source: FDA drug label (VALPROIC ACID), PAI Holdings, LLC dba PAI Pharma, effective January 24, 2025 (SPL set 7d5cb52e-37dd-4dfa-a6f4-09f9548846c6), 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 | Valproic acid | |
|---|---|---|
| Labeled for | Acid reflux and ulcers | Seizures and epilepsy, Migraine |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.236 per tablet 300 mg tablet | $0.243 per capsule 250 mg capsule |
| Shortage now | No current entry | Listed; available |
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