Drug interactions
Codeine + Lopinavir
Severity: Moderate
Codeine and Lopinavir: 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
Lopinavir/ritonavir may reduce CYP2D6-mediated conversion of codeine to morphine, which can weaken analgesia. Ritonavir also inhibits CYP3A4, shifting codeine toward norcodeine, and the net clinical effect is variable.
What this interaction means in plain words
Codeine and Lopinavir 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.
Codeine belongs to Musculoskeletal; Lopinavir belongs to Anti Virals.
Why it happens
Ritonavir-boosted lopinavir inhibits CYP2D6 and CYP3A4, reducing formation of morphine from codeine and altering overall opioid exposure.
What to do
Assess pain control and consider a non-prodrug opioid if analgesia is inadequate. Monitor for sedation and respiratory depression if the combination is started or stopped.
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 Codeine
- Alvimopan + Codeine Contraindicated
- Codeine + Isocarboxazid Contraindicated
- Codeine + Olanzapine / samidorphan Contraindicated
- Codeine + Phenelzine Contraindicated
- Codeine + Tranylcypromine Contraindicated
- Alfentanil + Codeine Major
Other interactions of Lopinavir
- Alfuzosin + Lopinavir Contraindicated
- Avanafil + Lopinavir Contraindicated
- Cisapride + Lopinavir Contraindicated
- Dronedarone + Lopinavir Contraindicated
- Eletriptan + Lopinavir Contraindicated
- Eplerenone + Lopinavir Contraindicated
Frequently asked questions
Can I take Codeine with Lopinavir?
MediHelp rates the interaction as moderate. Codeine and Lopinavir 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. Lopinavir/ritonavir may reduce CYP2D6-mediated conversion of codeine to morphine, which can weaken analgesia. Ritonavir also inhibits CYP3A4, shifting codeine toward norcodeine, and the net clinical effect is variable.
How serious is the interaction between Codeine and Lopinavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Assess pain control and consider a non-prodrug opioid if analgesia is inadequate. Monitor for sedation and respiratory depression if the combination is started or stopped.
What other medicines interact with Codeine?
MediHelp also lists interactions of Codeine with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Codeine page.
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