Ceritinib and Acetaminophen And Codeine: 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
Ceritinib
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.
Here's what's going on. Codeine is a medicine your body has to turn into its active pain-relieving form. Ceritinib (Zykadia) slows down one of the enzymes involved in handling codeine, so more codeine and morphine can build up in your body. That can make the opioid effects stronger, like heavy drowsiness, slowed breathing, or feeling very sedated.
This is a theoretical concern, meaning it's based on how the drugs work rather than lots of real-world reports. Still, because slowed breathing can be serious, it's worth taking seriously. Please keep taking both as prescribed and talk with your pharmacist or doctor, who can watch you closely and adjust your dose if needed.
Mechanism: Ceritinib inhibits CYP3A4, reducing metabolism of codeine and increasing exposure to codeine and its active metabolite morphine.
- Direction: Increased opioid effect (higher codeine/morphine concentrations).
- Risk: Enhanced or prolonged opioid adverse effects, including sedation and potentially fatal respiratory depression, especially when the inhibitor is added to a stable codeine regimen.
- Evidence: Theoretical; onset unspecified. Severity rated major.
- Management: Monitor for respiratory depression and sedation; codeine dose may need reduction and individualization until stable effects are observed. If ceritinib is discontinued, monitor for opioid withdrawal and consider upward dose adjustment.
What happens
Increased codeine and morphine exposure
Interaction Deep Dive
Concomitant use of codeine with CYP3A4 inhibitors has resulted in increased codeine and morphine concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of codeine is achieved. If concomitant use is needed, closely monitor patients for respiratory depression and sedation, and consider dose reduction of codeine until stable drug effects have been observed. If a CYP3A4 inhibitor is being discontinued, monitor patients for signs of opioid withdrawal, and consider increasing dose of codeine until stable drug effects have been observed12.
Why it happens (mechanism)
Inhibition of CYP3A4-mediated codeine metabolism
How to manage this interaction
The good news: your care team can manage this by tailoring your codeine dose and watching you more closely.
- Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise.
- Your team may reduce the codeine dose and monitor you for excessive sleepiness or slowed, shallow breathing, especially soon after starting ceritinib.
- If ceritinib is later stopped, they may watch for opioid withdrawal and adjust the codeine dose again.
- Tell your pharmacist or doctor right away about unusual drowsiness, confusion, or breathing changes.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Ceritinib and Acetaminophen And Codeine together?
Ceritinib can slow codeine breakdown and raise codeine and morphine levels, increasing the risk of heavy sedation and dangerously slow breathing. Keep taking both as prescribed and ask your care team to monitor you and adjust the codeine dose as needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Ceritinib and Acetaminophen And Codeine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Ceritinib and Acetaminophen And Codeine interaction managed?
The good news: your care team can manage this by tailoring your codeine dose and watching you more closely. Keep taking both medicines exactly as prescribed unless your prescriber tells you otherwise. Your team may reduce the codeine dose and monitor you for excessive sleepiness or slowed, shallow breathing, especially soon after starting ceritinib. If ceritinib is later stopped, they may watch fo… 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 Ceritinib or Acetaminophen And Codeine 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 a safer alternative to one of these medications for me?
References (2)
- Product Information: Codeine sulfate oral solution, codeine sulfate oral solution. Hikma Pharmaceuticals USA Inc(per FDA), Berkeley Heights, NJ, 2023. DailyMed
- Product Information: Codeine sulfate oral tablets, codeine sulfate oral tablets. Hikma Pharmaceuticals USA Inc. (per FDA), Berkeley Heights, NJ, 2023. DailyMed
Keep reading about Acetaminophen And Codeine
Keep reading about Ceritinib
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