Cimetidine and Valproate Interaction

Drug interaction information between Cimetidine and Valproate.

Cimetidine and Valproate have a documented major interaction in FDA labeling.

FDA drug labeling documents a major-severity interaction between Cimetidine and Valproate. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Cimetidine

H2 Receptor Antagonist

Drug B

Valproate

Anticonvulsant / Mood Stabilizer

How They Interact

Cimetidine does not interfere with how the body breaks down or clears valproate. This means the amount of valproate in your blood should remain stable.

FDA Label Information

Cimetidine and Ranitidine Cimetidine and ranitidine do not affect the clearance of valproate.

Frequently Asked Questions

What SPL severity band is on file for Cimetidine + Valproate?

Compiled FDA labeling labels this pair major. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Cimetidine has 77 labeled pairs on file vs Valproate's 41. In the major band specifically: Cimetidine has 4 (also Levofloxacin, Posaconazole, Risperidone); Valproate has 2 (also Ranitidine).

What mechanism field is on file for Cimetidine and Valproate?

Cimetidine does not interfere with how the body breaks down or clears valproate. This means the amount of valproate in your blood should remain stable.

Cimetidine carries more major-labeled pairs than Valproate

SPL source-record counts only. This page's band is major · classes on file: Cimetidine (H2 Receptor Antagonist); Valproate (Anticonvulsant / Mood Stabilizer).

Cimetidine has 4 major-labeled pairs vs Valproate's 2.

Cimetidine

4 major · 10 moderate · 63 minor · 77 total

Valproate

2 major · 3 moderate · 36 minor · 41 total

Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.