Lamotrigine and Sodium Valproate: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Lamotrigine and Sodium Valproate unless specifically directed by your doctor.
How Lamotrigine interacts with Sodium Valproate
Valproate inhibits UGT1A4-mediated glucuronidation of lamotrigine, doubling lamotrigine plasma levels and markedly increasing risk of serious skin reactions including Stevens-Johnson syndrome.
What you should do
Use a much slower lamotrigine titration (halve starting dose and weekly increments). Maximum maintenance dose is approximately one-half of monotherapy dose.
Key facts
Severity
Major — avoid combination
Mechanism
Valproate inhibits UGT1A4-mediated glucuronidation of lamotrigine, doubling lamotrigine plasma levels and markedly incre...
Action
Use a much slower lamotrigine titration (halve starting dose and weekly increments). Maximum maintenance dose is approxi...
Frequently asked questions
Can I take Lamotrigine and Sodium Valproate together?
No — this combination should generally be avoided. Use a much slower lamotrigine titration (halve starting dose and weekly increments). Maximum maintenance dose is approximately one-half of monotherapy dose.
What is the severity of this interaction?
The interaction between Lamotrigine and Sodium Valproate is classified as Major — avoid combination. Valproate inhibits UGT1A4-mediated glucuronidation of lamotrigine, doubling lamotrigine plasma levels and markedly increasing risk of serious skin reactions including Stevens-Johnson syndrome.
What should I do if I'm prescribed both?
Use a much slower lamotrigine titration (halve starting dose and weekly increments). Maximum maintenance dose is approximately one-half of monotherapy dose. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.