Drug interactions
Isoniazid + Pimavanserin
Severity: Moderate
Isoniazid and Pimavanserin: 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
Pimavanserin is metabolized mainly by CYP3A4 and prolongs the QT interval. Isoniazid may increase its exposure and the associated QT risk.
What this interaction means in plain words
Isoniazid and Pimavanserin 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 belongs to Anti Bacterial; Pimavanserin belongs to Central Nervous System.
Why it happens
Isoniazid inhibits CYP3A4, increasing pimavanserin concentrations.
What to do
Monitor the ECG and consider lowering the pimavanserin dose. Correct electrolyte abnormalities.
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 Pimavanserin
- Lefamulin + Pimavanserin Contraindicated
- Pimavanserin + Pimozide Contraindicated
- Pimavanserin + Vandetanib Contraindicated
- Adagrasib + Pimavanserin Major
- Amiodarone + Pimavanserin Major
- Amisulpride + Pimavanserin Major
Frequently asked questions
Can I take Isoniazid with Pimavanserin?
MediHelp rates the interaction as moderate. Isoniazid and Pimavanserin 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. Pimavanserin is metabolized mainly by CYP3A4 and prolongs the QT interval. Isoniazid may increase its exposure and the associated QT risk.
How serious is the interaction between Isoniazid and Pimavanserin?
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 the ECG and consider lowering the pimavanserin dose. Correct electrolyte abnormalities.
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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