Drug interactions
Fenfluramine + Risperidone
Severity: Moderate
Fenfluramine and Risperidone: 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
Risperidone blocks serotonin 5-HT2 receptors and could reduce the anticonvulsant effect of fenfluramine, which acts through serotonergic pathways. Additive sedation is also possible.
What this interaction means in plain words
Fenfluramine and Risperidone 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; Risperidone belongs to Central Nervous System.
Why it happens
Pharmacodynamic antagonism of serotonergic receptors by risperidone, with additive CNS effects.
What to do
Monitor seizure frequency and sedation when risperidone is used with fenfluramine, and reassess the need for the antipsychotic 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 Risperidone
- Ibutilide + Risperidone Contraindicated
- Risperidone + Vandetanib Contraindicated
- Adagrasib + Risperidone Major
- Amiodarone + Risperidone Major
- Amisulpride + Risperidone Major
- Amoxapine + Risperidone 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 Risperidone?
MediHelp rates the interaction as moderate. Fenfluramine and Risperidone 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. Risperidone blocks serotonin 5-HT2 receptors and could reduce the anticonvulsant effect of fenfluramine, which acts through serotonergic pathways. Additive sedation is also possible.
How serious is the interaction between Fenfluramine and Risperidone?
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 and sedation when risperidone is used with fenfluramine, and reassess the need for the antipsychotic if seizure control worsens.
What other medicines interact with Risperidone?
MediHelp also lists interactions of Risperidone with, for example, Ibutilide, Vandetanib, Adagrasib. The full list is on the Risperidone page.
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