Drug interactions
Fenfluramine + Olanzapine
Severity: Moderate
Fenfluramine 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
Fenfluramine acts by releasing serotonin and activating serotonin receptors, while olanzapine blocks several of them. This may reduce fenfluramine's antiseizure efficacy, and both can cause sedation.
What this interaction means in plain words
Fenfluramine 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.
Fenfluramine belongs to Central Nervous System; Olanzapine belongs to Central Nervous System.
Why it happens
Pharmacodynamic antagonism at serotonin receptors, plus additive CNS depression.
What to do
Monitor seizure frequency and sedation when combining the drugs. Reassess the need for olanzapine 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 Olanzapine
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 Olanzapine?
MediHelp rates the interaction as moderate. Fenfluramine 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. Fenfluramine acts by releasing serotonin and activating serotonin receptors, while olanzapine blocks several of them. This may reduce fenfluramine's antiseizure efficacy, and both can cause sedation.
How serious is the interaction between Fenfluramine 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 seizure frequency and sedation when combining the drugs. Reassess the need for olanzapine if seizure control worsens.
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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