Does Divalproex Sodium Interact with Lamotrigine?
Divalproex Sodium and Lamotrigine have a major drug interaction according to U.S. FDA drug labeling data. Valproate can inhibit lamotrigine metabolism and displace protein binding, requiring dosage adjustment of lamotrigine. The mechanism involves metabolism inhibition and protein binding displacement. 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
- Major
- Lamotrigine Class
- Anti-epileptic Agent
- Management
- Close medical supervision required
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Divalproex Sodium and Lamotrigine occurs because metabolism inhibition and protein binding displacement. Clinically, this means valproate can inhibit lamotrigine metabolism and displace protein binding, requiring dosage adjustment of lamotrigine. This is classified as a major interaction, meaning it could cause serious harm if not properly managed. Your healthcare provider may need to adjust dosages, substitute one medication, or increase monitoring frequency.
What To Tell Your Doctor or Pharmacist
If you are taking Divalproex Sodium and your doctor is considering prescribing Lamotrigine (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 how frequently you should be monitored while these are co-prescribed
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider