Drug interactions
Moxonidine + Promethazine
Severity: Moderate
Moxonidine 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
Moxonidine is a centrally acting antihypertensive that commonly causes drowsiness and dry mouth. Combined with promethazine, sedation, dizziness and hypotension may be more pronounced, especially in older adults.
What this interaction means in plain words
Moxonidine 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 and hypotensive effects from central alpha/imidazoline agonism and histamine H1 and alpha-adrenergic blockade.
What to do
Monitor blood pressure and level of sedation, especially when starting or increasing doses. Counsel patients about driving and rising slowly from sitting or lying positions.
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
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Frequently asked questions
Can I take Moxonidine with Promethazine?
MediHelp rates the interaction as moderate. Moxonidine 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. Moxonidine is a centrally acting antihypertensive that commonly causes drowsiness and dry mouth. Combined with promethazine, sedation, dizziness and hypotension may be more pronounced, especially in older adults.
How serious is the interaction between Moxonidine 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 blood pressure and level of sedation, especially when starting or increasing doses. Counsel patients about driving and rising slowly from sitting or lying positions.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Cabergoline, Dopamine, Ibutilide. The full list is on the Promethazine page.
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