Drug interactions
Lorcaserin + Pimavanserin
Severity: Moderate
Lorcaserin and Pimavanserin: 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 pimavanserin is a 5-HT2A inverse agonist and antagonist. Combining them could theoretically alter serotonergic tone, with a remote risk of serotonin toxicity. The clinical significance is uncertain, and lorcaserin has been withdrawn from many markets.
What this interaction means in plain words
Lorcaserin and Pimavanserin 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
Overlapping serotonergic receptor activity; a pharmacodynamic interaction that is theoretical and not well established.
What to do
Monitor for agitation, tremor, hyperthermia, clonus and autonomic instability when the two are started together or doses are raised. Stop one of the drugs if features of serotonin toxicity develop.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Lorcaserin and Pimavanserin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Pimavanserin
- Lefamulin + Pimavanserin Contraindicated
- Pimavanserin + Pimozide Contraindicated
- Pimavanserin + Vandetanib Contraindicated
- Adagrasib + Pimavanserin Major
- Amiodarone + Pimavanserin Major
- Amisulpride + Pimavanserin Major
Frequently asked questions
Can I take Lorcaserin with Pimavanserin?
MediHelp rates the interaction as moderate. Lorcaserin and Pimavanserin 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 pimavanserin is a 5-HT2A inverse agonist and antagonist. Combining them could theoretically alter serotonergic tone, with a remote risk of serotonin toxicity. The clinical significance is uncertain, and lorcaserin has been withdrawn from many markets.
How serious is the interaction between Lorcaserin and Pimavanserin?
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, tremor, hyperthermia, clonus and autonomic instability when the two are started together or doses are raised. Stop one of the drugs if features of serotonin toxicity develop.
What other medicines interact with Pimavanserin?
MediHelp also lists interactions of Pimavanserin with, for example, Lefamulin, Pimozide, Vandetanib. The full list is on the Pimavanserin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
