Drug interactions
Lemborexant + Promethazine
Severity: Moderate
Lemborexant 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
Both agents cause sedation, so combined use can increase drowsiness and next-day psychomotor impairment. Promethazine is also a CYP2B6 substrate, but any effect of lemborexant on its levels is of uncertain relevance.
What this interaction means in plain words
Lemborexant 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.
Lemborexant belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Additive CNS depression from H1 antagonism and orexin receptor antagonism.
What to do
Avoid routine combination; if both are needed, use the lowest effective doses and warn the patient about daytime impairment and driving.
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
Other interactions of Lemborexant
Frequently asked questions
Can I take Lemborexant with Promethazine?
MediHelp rates the interaction as moderate. Lemborexant 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. Both agents cause sedation, so combined use can increase drowsiness and next-day psychomotor impairment. Promethazine is also a CYP2B6 substrate, but any effect of lemborexant on its levels is of uncertain relevance.
How serious is the interaction between Lemborexant 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: Avoid routine combination; if both are needed, use the lowest effective doses and warn the patient about daytime impairment and driving.
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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