Drug interactions
Kava + Promethazine
Severity: Moderate
Kava and Promethazine: 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
Kava has sedative and anxiolytic effects and may add to promethazine-related CNS depression, causing drowsiness and impaired coordination. Kava has also been linked to hepatotoxicity, which adds concern in patients taking other hepatically active drugs.
What this interaction means in plain words
Kava and Promethazine 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.
Why it happens
Additive CNS depression; kavalactones enhance GABAergic transmission while promethazine blocks central H1 receptors.
What to do
Advise avoiding kava while taking promethazine, and warn against driving or operating machinery if used. Monitor for excessive sedation and for signs of liver injury.
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 Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Frequently asked questions
Can I take Kava with Promethazine?
MediHelp rates the interaction as moderate. Kava and Promethazine 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. Kava has sedative and anxiolytic effects and may add to promethazine-related CNS depression, causing drowsiness and impaired coordination. Kava has also been linked to hepatotoxicity, which adds concern in patients taking other hepatically active drugs.
How serious is the interaction between Kava and Promethazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise avoiding kava while taking promethazine, and warn against driving or operating machinery if used. Monitor for excessive sedation and for signs of liver injury.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Promethazine page.
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