Drug interactions
Lamotrigine + Rifampin
Severity: Moderate
Lamotrigine and Rifampin: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Rifampin substantially lowers lamotrigine exposure, which may cause loss of seizure control. The effect fades after rifampin is discontinued.
What this interaction means in plain words
Lamotrigine and Rifampin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Rifampin induces hepatic glucuronidation of lamotrigine.
What to do
Monitor seizure control and increase the lamotrigine dose as needed during rifampin therapy. Reduce the dose again after rifampin is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Lamotrigine
Frequently asked questions
Can I take Lamotrigine with Rifampin?
MediHelp rates the interaction as moderate. Lamotrigine and Rifampin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Rifampin substantially lowers lamotrigine exposure, which may cause loss of seizure control. The effect fades after rifampin is discontinued.
How serious is the interaction between Lamotrigine and Rifampin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor seizure control and increase the lamotrigine dose as needed during rifampin therapy. Reduce the dose again after rifampin is stopped.
What other medicines interact with Lamotrigine?
MediHelp also lists interactions of Lamotrigine with, for example, Desogestrel-ethinyl estradiol, Divalproex, Dofetilide. The full list is on the Lamotrigine page.
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