Drug interactions
Meperidine + Promethazine
Severity: Major
Meperidine and Promethazine: major 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 enhances the sedative and respiratory depressant effects of opioids such as meperidine, and the combination has been used for premedication. Profound sedation, hypotension and respiratory depression can occur, and meperidine's neurotoxic metabolite adds seizure risk with repeated dosing.
What this interaction means in plain words
Meperidine and Promethazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Meperidine belongs to Musculoskeletal; Promethazine belongs to Respiratory.
Why it happens
Additive CNS and respiratory depression via opioid receptor agonism and H1 antagonism.
What to do
Start with reduced opioid doses and monitor respiratory rate, oxygen saturation and sedation closely. Avoid in patients at risk of respiratory compromise.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Meperidine
- Alvimopan + Meperidine Contraindicated
- Isocarboxazid + Meperidine Contraindicated
- Meperidine + Methylene blue Contraindicated
- Meperidine + Olanzapine / samidorphan Contraindicated
- Meperidine + Phenelzine Contraindicated
- Meperidine + Procarbazine Contraindicated
Frequently asked questions
Can I take Meperidine with Promethazine?
MediHelp rates the interaction as major. Meperidine and Promethazine can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Promethazine enhances the sedative and respiratory depressant effects of opioids such as meperidine, and the combination has been used for premedication. Profound sedation, hypotension and respiratory depression can occur, and meperidine's neurotoxic metabolite adds seizure risk with repeated dosing.
How serious is the interaction between Meperidine and Promethazine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with reduced opioid doses and monitor respiratory rate, oxygen saturation and sedation closely. Avoid in patients at risk of respiratory compromise.
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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