Drug interactions
Lamotrigine + Olanzapine
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.
Overview
Olanzapine may decrease lamotrigine plasma concentrations, potentially reducing seizure or mood-stabilizing efficacy; additive CNS depressant effects (e.g., dizziness, sedation) may also occur.
Mechanism of action
Pharmacokinetic: possible induction of lamotrigine glucuronidation (UGT1A4) by olanzapine, lowering exposure. Pharmacodynamic: additive CNS depressant effects.
Clinical management
Monitor clinical response to lamotrigine when initiating or discontinuing olanzapine; consider lamotrigine dose adjustment based on efficacy and tolerability. If available, check lamotrigine serum concentrations. Counsel on sedation and avoid other CNS depressants as appropriate.
Drug reference
References
- Lamotrigine: Drug Interactions — Lexicomp
- Olanzapine: Drug Interactions — Lexicomp
- Lamotrigine: Pharmacology, administration, and side effects — UpToDate
Frequently asked questions
Can I take Lamotrigine with Olanzapine?
The interaction is rated: Moderate. Olanzapine may decrease lamotrigine plasma concentrations, potentially reducing seizure or mood-stabilizing efficacy; additive CNS depressant effects (e.g., dizziness, sedation) may also occur.
How serious is the interaction between Lamotrigine and Olanzapine?
The interaction is rated: Moderate. Evidence level: Moderate.
How is the interaction between Lamotrigine and Olanzapine managed?
Monitor clinical response to lamotrigine when initiating or discontinuing olanzapine; consider lamotrigine dose adjustment based on efficacy and tolerability. If available, check lamotrigine serum concentrations. Counsel on sedation and avoid other CNS depressants as appropriate.
Why do Lamotrigine and Olanzapine interact?
Pharmacokinetic: possible induction of lamotrigine glucuronidation (UGT1A4) by olanzapine, lowering exposure. Pharmacodynamic: additive CNS depressant effects.
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