Drug interactions
Codeine + Promethazine
Severity: Major
Codeine and Promethazine: major interaction.
Last updated Sources: US FDA label
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 codeine both depress the CNS, so together they can cause marked sedation, respiratory depression and hypotension. Opioid labeling warns about concomitant use with sedating drugs, and this is especially relevant in children and elderly patients.
What this interaction means in plain words
Codeine 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.
Codeine belongs to Musculoskeletal; Promethazine belongs to Respiratory.
Why it happens
Additive central nervous system and respiratory depression.
What to do
Avoid use in children, and in adults use the lowest effective doses for the shortest time while monitoring sedation and breathing. Counsel patients to avoid alcohol and other depressants.
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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References
Other interactions of Promethazine
- Cabergoline + Promethazine Contraindicated
- Dopamine + Promethazine Contraindicated
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
Other interactions of Codeine
- Alvimopan + Codeine Contraindicated
- Codeine + Isocarboxazid Contraindicated
- Codeine + Olanzapine / samidorphan Contraindicated
- Codeine + Phenelzine Contraindicated
- Codeine + Tranylcypromine Contraindicated
- Alfentanil + Codeine Major
Frequently asked questions
Can I take Codeine with Promethazine?
MediHelp rates the interaction as major. Codeine 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 and codeine both depress the CNS, so together they can cause marked sedation, respiratory depression and hypotension. Opioid labeling warns about concomitant use with sedating drugs, and this is especially relevant in children and elderly patients.
How serious is the interaction between Codeine 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: Avoid use in children, and in adults use the lowest effective doses for the shortest time while monitoring sedation and breathing. Counsel patients to avoid alcohol and other depressants.
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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