Drug interactions
Lamotrigine + Ritonavir
Severity: Moderate
Lamotrigine and Ritonavir: 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
Ritonavir, particularly as a booster with other protease inhibitors, reduces lamotrigine concentrations and may compromise seizure control. The effect reverses when it is stopped.
What this interaction means in plain words
Lamotrigine and Ritonavir 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.
Lamotrigine belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir induces lamotrigine glucuronidation.
What to do
Monitor seizure control and adjust the lamotrigine dose when ritonavir is started, stopped or changed. Consider lamotrigine level monitoring.
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
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Lamotrigine with Ritonavir?
MediHelp rates the interaction as moderate. Lamotrigine and Ritonavir 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. Ritonavir, particularly as a booster with other protease inhibitors, reduces lamotrigine concentrations and may compromise seizure control. The effect reverses when it is stopped.
How serious is the interaction between Lamotrigine and Ritonavir?
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 adjust the lamotrigine dose when ritonavir is started, stopped or changed. Consider lamotrigine level monitoring.
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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