Does Valproate Sodium Interact with Acetylsalicylic Acid?
Valproate Sodium and Acetylsalicylic Acid have a moderate drug interaction according to U.S. FDA drug labeling data. Aspirin decreases protein binding of valproate and inhibits its metabolism, increasing valproate free fraction 4-fold and decreasing β-oxidation pathway. Monitoring of valproate concentrations is recommended. The mechanism involves displacement of protein binding and inhibition of β-oxidation metabolism. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Moderate
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Valproate Sodium and Acetylsalicylic Acid occurs because displacement of protein binding and inhibition of β-oxidation metabolism. Clinically, this means aspirin decreases protein binding of valproate and inhibits its metabolism, increasing valproate free fraction 4-fold and decreasing β-oxidation pathway. monitoring of valproate concentrations is recommended. This is classified as a moderate interaction. While it may not require stopping either medication, your healthcare provider should be aware you are taking both so they can monitor for potential effects and adjust treatment if necessary.
What To Tell Your Doctor or Pharmacist
If you are taking Valproate Sodium and your doctor is considering prescribing Acetylsalicylic Acid (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider