Drug interactions
Fenfluramine + Pimavanserin
Severity: Moderate
Fenfluramine 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
Fenfluramine works through serotonergic activity, and pimavanserin blocks 5-HT2A receptors. Combined use may reduce fenfluramine's anticonvulsant effect.
What this interaction means in plain words
Fenfluramine 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.
Fenfluramine belongs to Central Nervous System; Pimavanserin belongs to Central Nervous System.
Why it happens
Pharmacodynamic antagonism at serotonin receptors.
What to do
Monitor seizure frequency when pimavanserin is started with fenfluramine. Reassess the need for pimavanserin or adjust fenfluramine therapy if seizure control worsens.
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 Pimavanserin
- Lefamulin + Pimavanserin Contraindicated
- Pimavanserin + Pimozide Contraindicated
- Pimavanserin + Vandetanib Contraindicated
- Adagrasib + Pimavanserin Major
- Amiodarone + Pimavanserin Major
- Amisulpride + Pimavanserin Major
Other interactions of Fenfluramine
- Fenfluramine + Isocarboxazid Contraindicated
- Fenfluramine + Linezolid Contraindicated
- Fenfluramine + Phenelzine Contraindicated
- Fenfluramine + Selegiline Contraindicated
- Fenfluramine + Tranylcypromine Contraindicated
- Almotriptan + Fenfluramine Major
Frequently asked questions
Can I take Fenfluramine with Pimavanserin?
MediHelp rates the interaction as moderate. Fenfluramine 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. Fenfluramine works through serotonergic activity, and pimavanserin blocks 5-HT2A receptors. Combined use may reduce fenfluramine's anticonvulsant effect.
How serious is the interaction between Fenfluramine 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 seizure frequency when pimavanserin is started with fenfluramine. Reassess the need for pimavanserin or adjust fenfluramine therapy if seizure control worsens.
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.
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