Drug interactions
Lamotrigine + Quetiapine
Severity: Moderate
Lamotrigine and Quetiapine: moderate interaction.
Last updated Sources: US FDA label
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
Additive CNS depression (sedation, dizziness, psychomotor impairment). Therapeutic drug monitoring data also suggest lamotrigine may lower quetiapine serum concentrations, which could reduce quetiapine efficacy.
What this interaction means in plain words
Lamotrigine and Quetiapine 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; Quetiapine belongs to Central Nervous System.
Why it happens
Pharmacodynamic: additive CNS depressant effects. Possible pharmacokinetic effect: lamotrigine may increase quetiapine glucuronidation (proposed, not confirmed).
What to do
Monitor for excessive sedation, dizziness, and falls, especially during titration and in elderly patients. Monitor quetiapine clinical response.
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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References
- Quetiapine and drug interactions: evidence from a routine therapeutic drug monitoring service (Castberg I, Skogvoll E, Spigset O. J Clin Psychiatry. 2007) — PubMed
- Quetiapine Prescribing Information - Drug Interactions (CNS-acting drugs) — FDA Label
Other interactions of Quetiapine
- Adagrasib + Quetiapine Major
- Amiodarone + Quetiapine Major
- Amisulpride + Quetiapine Major
- Amoxapine + Quetiapine Major
- Anagrelide + Quetiapine Major
- Apalutamide + Quetiapine Major
Other interactions of Lamotrigine
Frequently asked questions
Can I take Lamotrigine with Quetiapine?
MediHelp rates the interaction as moderate. Lamotrigine and Quetiapine 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. Additive CNS depression (sedation, dizziness, psychomotor impairment). Therapeutic drug monitoring data also suggest lamotrigine may lower quetiapine serum concentrations, which could reduce quetiapine efficacy.
How serious is the interaction between Lamotrigine and Quetiapine?
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 for excessive sedation, dizziness, and falls, especially during titration and in elderly patients. Monitor quetiapine clinical response.
What other medicines interact with Quetiapine?
MediHelp also lists interactions of Quetiapine with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Quetiapine page.
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