Drug interactions
Clozapine + Fenfluramine
Severity: Moderate
Clozapine and Fenfluramine: 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 acts through serotonin release and serotonin receptor agonism, while clozapine strongly blocks several serotonin receptors, so fenfluramine's anticonvulsant effect may be reduced. Both agents also affect the central nervous system, and fenfluramine can cause somnolence. Clozapine itself lowers the seizure threshold, which is relevant in patients treated for epilepsy.
What this interaction means in plain words
Clozapine and Fenfluramine 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.
Clozapine belongs to Central Nervous System; Fenfluramine belongs to Central Nervous System.
Why it happens
Clozapine antagonism of serotonin receptors may oppose fenfluramine's serotonergic activity, with additive CNS effects.
What to do
Monitor seizure frequency and psychiatric status, and watch for excessive sedation. Reassess the need for clozapine in patients with epilepsy.
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 Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine 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 Clozapine with Fenfluramine?
MediHelp rates the interaction as moderate. Clozapine and Fenfluramine 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 acts through serotonin release and serotonin receptor agonism, while clozapine strongly blocks several serotonin receptors, so fenfluramine's anticonvulsant effect may be reduced. Both agents also affect the central nervous system, and fenfluramine can cause somnolence. Clozapine itself lowers the seizure threshold, which is relevant in patients treated for epilepsy.
How serious is the interaction between Clozapine and Fenfluramine?
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 psychiatric status, and watch for excessive sedation. Reassess the need for clozapine in patients with epilepsy.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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