Drug interactions
Fluvoxamine + Isoniazid
Severity: Moderate
Fluvoxamine and Isoniazid: 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
Isoniazid's weak MAO inhibition combined with fluvoxamine may theoretically raise the risk of serotonin toxicity. Clinical reports are uncommon.
What this interaction means in plain words
Fluvoxamine and Isoniazid 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.
Fluvoxamine belongs to Central Nervous System; Isoniazid belongs to Anti Bacterial.
Why it happens
Additive serotonergic effect from weak MAO inhibition and serotonin reuptake inhibition.
What to do
Monitor for tremor, agitation, sweating, hyperreflexia and fever, particularly early in therapy. Stop one agent if serotonin syndrome is suspected.
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 Isoniazid
Other interactions of Fluvoxamine
- Agomelatine + Fluvoxamine Contraindicated
- Alosetron + Fluvoxamine Contraindicated
- Fezolinetant + Fluvoxamine Contraindicated
- Fluvoxamine + Isocarboxazid Contraindicated
- Fluvoxamine + Mavacamten Contraindicated
- Fluvoxamine + Methylene blue Contraindicated
Frequently asked questions
Can I take Fluvoxamine with Isoniazid?
MediHelp rates the interaction as moderate. Fluvoxamine and Isoniazid 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. Isoniazid's weak MAO inhibition combined with fluvoxamine may theoretically raise the risk of serotonin toxicity. Clinical reports are uncommon.
How serious is the interaction between Fluvoxamine and Isoniazid?
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 tremor, agitation, sweating, hyperreflexia and fever, particularly early in therapy. Stop one agent if serotonin syndrome is suspected.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
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