Drug interactions
Fexinidazole + Promethazine
Severity: Moderate
Fexinidazole 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
Fexinidazole induces CYP2B6 according to its labeling, which may lower exposure to CYP2B6 substrates. Promethazine is metabolized mainly by CYP2D6 and other pathways, with CYP2B6 playing at most a minor role. A clinically meaningful loss of promethazine effect is therefore uncertain.
What this interaction means in plain words
Fexinidazole 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
Fexinidazole may induce CYP2B6, potentially increasing promethazine clearance, although the contribution of this enzyme is minor.
What to do
Monitor for reduced antiemetic or antihistaminic effect and increase the dose if needed. Consider an alternative agent if efficacy is lost during fexinidazole treatment.
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 Fexinidazole with Promethazine?
MediHelp rates the interaction as moderate. Fexinidazole 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. Fexinidazole induces CYP2B6 according to its labeling, which may lower exposure to CYP2B6 substrates. Promethazine is metabolized mainly by CYP2D6 and other pathways, with CYP2B6 playing at most a minor role. A clinically meaningful loss of promethazine effect is therefore uncertain.
How serious is the interaction between Fexinidazole 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: Monitor for reduced antiemetic or antihistaminic effect and increase the dose if needed. Consider an alternative agent if efficacy is lost during fexinidazole treatment.
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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