Drug interactions
Alprazolam + Promethazine
Severity: Moderate
Alprazolam 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
Promethazine and alprazolam both depress the central nervous system. Together they can cause excessive sedation, impaired psychomotor function and, at higher doses, respiratory depression.
What this interaction means in plain words
Alprazolam 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.
Alprazolam belongs to Central Nervous System; Promethazine belongs to Respiratory.
Why it happens
Additive CNS depression through H1 antagonism and GABA-A potentiation.
What to do
Use the lowest effective doses and monitor sedation, especially in older adults. Advise patients to avoid alcohol 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
Other interactions of Alprazolam
- Alprazolam + Calcium / magnesium / potassium / sodium oxybates Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Alprazolam + Levoketoconazole Contraindicated
- Alprazolam + Sodium oxybate Contraindicated
- Alfentanil + Alprazolam Major
Frequently asked questions
Can I take Alprazolam with Promethazine?
MediHelp rates the interaction as moderate. Alprazolam 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. Promethazine and alprazolam both depress the central nervous system. Together they can cause excessive sedation, impaired psychomotor function and, at higher doses, respiratory depression.
How serious is the interaction between Alprazolam 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: Use the lowest effective doses and monitor sedation, especially in older adults. Advise patients to avoid alcohol and driving.
What other medicines interact with Promethazine?
MediHelp also lists interactions of Promethazine with, for example, Alfentanil. The full list is on the Promethazine page.
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