Drug interactions
Fenfluramine + Metaxalone
Severity: Moderate
Fenfluramine and Metaxalone: 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 is a serotonin-releasing antiseizure drug that commonly causes somnolence and fatigue. Metaxalone has weak serotonergic activity, so combined use may raise sedation and, rarely, the risk of serotonin toxicity.
What this interaction means in plain words
Fenfluramine and Metaxalone 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; Metaxalone belongs to Musculoskeletal.
Why it happens
Additive CNS effects, with a possible minor serotonergic contribution from metaxalone.
What to do
Monitor for excess sedation and for signs of serotonin syndrome such as agitation, tremor, sweating and hyperthermia. Reduce doses if symptoms 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?
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Other interactions of Metaxalone
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 Metaxalone?
MediHelp rates the interaction as moderate. Fenfluramine and Metaxalone 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 is a serotonin-releasing antiseizure drug that commonly causes somnolence and fatigue. Metaxalone has weak serotonergic activity, so combined use may raise sedation and, rarely, the risk of serotonin toxicity.
How serious is the interaction between Fenfluramine and Metaxalone?
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 excess sedation and for signs of serotonin syndrome such as agitation, tremor, sweating and hyperthermia. Reduce doses if symptoms develop.
What other medicines interact with Metaxalone?
MediHelp also lists interactions of Metaxalone with, for example, Alfentanil, Belladonna and opium, Benzhydrocodone / acetaminophen. The full list is on the Metaxalone page.
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