Carbamazepine and Lamotrigine: Drug Interaction Guide

Quick answer: This combination requires caution. Carbamazepine and Lamotrigine can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Carbamazepine interacts with Lamotrigine

Carbamazepine induces UGT1A4 glucuronidation of lamotrigine, reducing lamotrigine serum concentrations by approximately 40-50% and risk of loss of seizure control.

What you should do

Increase lamotrigine maintenance dose (typically up to 400-700 mg/day) when used with carbamazepine, and titrate based on clinical response and plasma levels.

Key facts

Severity

Moderate — caution required

Mechanism

Carbamazepine induces UGT1A4 glucuronidation of lamotrigine, reducing lamotrigine serum concentrations by approximately ...

Action

Increase lamotrigine maintenance dose (typically up to 400-700 mg/day) when used with carbamazepine, and titrate based o...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Carbamazepine and Lamotrigine together?

With caution. Increase lamotrigine maintenance dose (typically up to 400-700 mg/day) when used with carbamazepine, and titrate based on clinical response and plasma levels.

What is the severity of this interaction?

The interaction between Carbamazepine and Lamotrigine is classified as Moderate — caution required. Carbamazepine induces UGT1A4 glucuronidation of lamotrigine, reducing lamotrigine serum concentrations by approximately 40-50% and risk of loss of seizure control.

What should I do if I'm prescribed both?

Increase lamotrigine maintenance dose (typically up to 400-700 mg/day) when used with carbamazepine, and titrate based on clinical response and plasma levels. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.