Lorazepam and Valproate Interaction
Drug interaction information between Lorazepam and Valproate.
Lorazepam and Valproate have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Lorazepam 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.
How They Interact
Valproate slows down how fast the liver breaks down lorazepam, which causes the drug to build up in the body.
FDA Label Information
Concurrent administration of lorazepam with valproate results in increased plasma concentrations and reduced clearance of lorazepam. Lorazepam dosage should be reduced to approximately 50% when coadministered with valproate. The effects of probenecid and valproate on lorazepam may be due to inhibition of glucuronidation.
Lorazepam Also Interacts With
- Clozapine minor
- Probenecid minor
- Theophylline minor
- Aripiprazole minor
- Clarithromycin minor
Valproate Also Interacts With
- Ranitidine major
- Cimetidine major
- Clarithromycin moderate
- Lidocaine Topical moderate
- Risperidone moderate
Frequently Asked Questions
What SPL severity band is on file for Lorazepam + Valproate?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Valproate has 41 labeled pairs on file vs Lorazepam's 11. In the minor band specifically: Lorazepam has 11 (also Clozapine, Probenecid, Theophylline, Aripiprazole); Valproate has 36 (also Aspirin, Clonazepam, Topiramate, Amitriptyline).
What mechanism field is on file for Lorazepam and Valproate?
Valproate slows down how fast the liver breaks down lorazepam, which causes the drug to build up in the body.
Valproate carries more major-labeled pairs than Lorazepam
SPL source-record counts only. This page's band is minor · classes on file: Lorazepam (Benzodiazepine); Valproate (Anticonvulsant / Mood Stabilizer).
Valproate has 2 major-labeled pairs vs Lorazepam's 0. This page itself is in the minor band, not the major band.
0 major · 0 moderate · 11 minor · 11 total
- Other minor peers for Lorazepam
- Clozapine
- Probenecid
- Theophylline
- Aripiprazole
2 major · 3 moderate · 36 minor · 41 total
- Other minor peers for Valproate
- Aspirin
- Clonazepam
- Topiramate
- Amitriptyline
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.
Read our methodology - how this data is sourced, computed, and verified.