Acetaminophen And Codeine and Artemether: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jun 30, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Artemether
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
You've been prescribed acetaminophen with codeine for pain along with artemether (a medicine used to treat malaria). Here's what's worth knowing. Codeine is a prodrug, which means your body has to change it into its active pain-relieving form. Artemether may speed up some of the liver's drug-processing pathways. In theory, this could lower the amount of the pain medicine in your body and make it work a little less well.
This is based on theory, not strong proof, so please don't worry. Keep taking both exactly as prescribed, and if your pain relief seems weaker than expected, let your pharmacist or doctor know so they can help.
Mechanism: Artemether (typically artemether/lumefantrine) may induce CYP3A4, potentially increasing metabolism of CYP3A4 substrates and reducing their exposure.
- Direction: Reduced CYP3A4-substrate exposure/efficacy. For codeine, CYP3A4 induction shunts more drug down the N-demethylation (inactive) pathway; net analgesic effect may be attenuated. Acetaminophen clearance is minimally CYP3A4-dependent.
- Evidence: Theoretical; magnitude unquantified.
- Onset: Unspecified.
- Management: Use caution; monitor analgesic response over the short antimalarial course. Dose may be individualized by the care team if efficacy appears reduced.
What happens
Reduced CYP3A4 substrate exposure and reduced efficacy of CYP3A4 substrate
Interaction Deep Dive
Exert caution when artemether/lumefantrine is coadministered with CYP3A4 substrates as it may reduce CYP3A4 substrates exposure, which may reduce efficacy of CYP3A4 substrates1.
Why it happens (mechanism)
Induction of CYP3A4-substrate metabolism by artemether/lumefantrine
How to manage this interaction
The good news is this is a theoretical concern, and your care team can manage it easily.
- Keep taking both exactly as prescribed unless your prescriber tells you otherwise.
- Artemether is usually a short malaria treatment course, so any effect is temporary.
- Watch for weaker-than-expected pain relief from the acetaminophen/codeine, and report it.
- Your pain-medicine dose may need to be adjusted and individualized by your care team, and they may monitor how well it is working more closely.
If you're unsure, ask your pharmacist or doctor to review both medicines together.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Acetaminophen And Codeine and Artemether together?
Artemether may slightly reduce how well your acetaminophen/codeine works for pain, but this is only theoretical. Keep taking both as prescribed and tell your care team if your pain relief seems weaker. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Artemether interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Acetaminophen And Codeine and Artemether interaction managed?
The good news is this is a theoretical concern, and your care team can manage it easily. Keep taking both exactly as prescribed unless your prescriber tells you otherwise. Artemether is usually a short malaria treatment course, so any effect is temporary. Watch for weaker-than-expected pain relief from the acetaminophen/codeine, and report it. Your pain-medicine dose may need to be adjusted and in… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Acetaminophen And Codeine or Artemether need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Product Information: COARTEM® oral tablets, artemether lumefantrine oral tablets. Novartis Pharmaceuticals Corporation (per DailyMed), East Hanover, NJ, 2025. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Artemether
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