Drug interactions
Lorcaserin + Olanzapine
Severity: Moderate
Lorcaserin and Olanzapine: 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
Lorcaserin is a serotonin 5-HT2C agonist, and combining it with an antipsychotic carries a theoretical risk of serotonin toxicity. Olanzapine's dopamine blockade could also add to the risk of neuroleptic malignant syndrome. Lorcaserin has been withdrawn from many markets, and the reported risk comes largely from labeling and prediction.
What this interaction means in plain words
Lorcaserin and Olanzapine 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
Possible additive serotonergic activity combined with dopamine antagonism; 5-HT2C agonism may oppose olanzapine's effects, but the mechanism is not firmly established.
What to do
Monitor for agitation, hyperthermia, tremor, clonus, rigidity and autonomic instability, and stop lorcaserin if these appear. Avoid the combination where an alternative weight-management option exists.
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 Olanzapine
Frequently asked questions
Can I take Lorcaserin with Olanzapine?
MediHelp rates the interaction as moderate. Lorcaserin and Olanzapine 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. Lorcaserin is a serotonin 5-HT2C agonist, and combining it with an antipsychotic carries a theoretical risk of serotonin toxicity. Olanzapine's dopamine blockade could also add to the risk of neuroleptic malignant syndrome. Lorcaserin has been withdrawn from many markets, and the reported risk comes largely from labeling and prediction.
How serious is the interaction between Lorcaserin and Olanzapine?
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 agitation, hyperthermia, tremor, clonus, rigidity and autonomic instability, and stop lorcaserin if these appear. Avoid the combination where an alternative weight-management option exists.
What other medicines interact with Olanzapine?
MediHelp also lists interactions of Olanzapine with, for example, Amisulpride, Amoxapine, Apomorphine. The full list is on the Olanzapine page.
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