Acetaminophen And Codeine and Imatinib: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 1, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Acetaminophen And Codeine
Imatinib
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.
Your pain medicine contains acetaminophen (Tylenol), and you're also taking imatinib (Gleevec) for your condition. Imatinib can slow down how your body breaks down acetaminophen, so the acetaminophen can build up. Since both acetaminophen and imatinib are processed by the liver, taking acetaminophen regularly over time could put extra stress on your liver.
This concern is mostly based on theory and a few reports, not strong proof, so please don't panic. Keep taking both as prescribed. Your care team can manage this easily by checking your liver with blood tests. Let your pharmacist or doctor know you take both, especially if you use acetaminophen often.
Effect: Predicted increase in acetaminophen exposure via imatinib inhibition of UGT-mediated glucuronidation, raising hepatotoxicity risk with chronic acetaminophen use. Neither agent's opioid component (codeine) is implicated here; the concern is the acetaminophen constituent.
- Direction/magnitude: In-vitro PK modeling predicts ~22% increase in acetaminophen AUC with imatinib 200 mg/day; a fatal acute liver failure case is reported with imatinib 400 mg/day plus chronic acetaminophen.
- Evidence: Theoretical/in-vitro plus isolated case report.
- Onset: Unspecified.
- Management: Monitor LFTs during concurrent therapy; discontinue if transaminases rise. Limit chronic/high-dose acetaminophen where feasible.
What happens
Increased acetaminophen levels
Interaction Deep Dive
When chronic acetaminophen dosing is combined with imatinib, acetaminophen concentrations may rise and hepatoxicity may occur, since imatinib inhibits the UGT-mediated metabolism of acetaminophen. An in-vitro pharmacokinetic study predicted that giving imatinib 200 mg daily together with acetaminophen would produce a 22% rise in acetaminophen AUC 4. A case report described fatal acute liver failure in a 51-year old woman with chronic myeloid leukemia who was being treated with imatinib 400 mg/day while also taking chronic daily acetaminophen doses ranging from 500 to 1000 mg. Because hepatoxicity is possible when acetaminophen is taken chronically by a patient on imatinib, liver function tests should be monitored closely throughout treatment, and therapy should be stopped if liver function tests become elevated 3.
Why it happens (mechanism)
Inhibition of UGT-mediated metabolism of acetaminophen by imatinib
How to manage this interaction
Keep taking both medicines as prescribed unless your care team tells you otherwise. The main concern is with regular, ongoing acetaminophen use rather than an occasional dose.
- Your team may monitor your liver with blood tests (LFTs) while you're on both, and will adjust your plan if those tests change.
- Tell your pharmacist or prescriber if you take acetaminophen (Tylenol) frequently, and watch for signs like yellowing skin or eyes, dark urine, belly pain, or unusual tiredness.
- Check other over-the-counter products, since many contain hidden acetaminophen.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
1 report — tap to read
a) A 51-year old woman with chronic myeloid leukemia who was receiving imatinib 400 mg/day and taking chronic daily acetaminophen doses of 500 to 1000 mg experienced fatal acute liver failure. After 5 months of imatinib therapy, the patient developed asthenia and started taking acetaminophen. She presented with elevated aminotransferases and a normal bilirubin. Even though imatinib was stopped, her liver function tests deteriorated and she developed jaundice and severe hepatitis with coagulopathy (prothrombin time 30% and clotting factor V level 19%). Ultrasound showed a reduced-size, homogenous liver. Testing for viral and autoimmune hepatitis was negative. The patient's condition continued to worsen with rising bilirubin, a marked decline in clotting factor V, and grade 3 encephalopathy, and she died after cardiac arrest 3.
Common questions
Can I take Acetaminophen And Codeine and Imatinib together?
Regular acetaminophen while on imatinib may raise acetaminophen levels and stress your liver, so your doctor may check liver blood tests; keep taking both as prescribed and report any signs of liver trouble. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Acetaminophen And Codeine and Imatinib 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 Acetaminophen And Codeine and Imatinib interaction managed?
Keep taking both medicines as prescribed unless your care team tells you otherwise. The main concern is with regular, ongoing acetaminophen use rather than an occasional dose. Your team may monitor your liver with blood tests (LFTs) while you're on both, and will adjust your plan if those tests change. Tell your pharmacist or prescriber if you take acetaminophen (Tylenol) frequently, and watch for… 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 Imatinib 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 (4)
- 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
- Ridruejo E, Cacchione R, Villamil AG, et al: Imatinib-induced fatal acute liver failure. World J Gastroenterol 2007; 13(48):6608-111. PubMed
- Liu Y, Ramirez J, & Ratain MJ: Inhibition of paracetamol glucuronidation by tyrosine kinase inhibitors. Br J Clin Pharmacol 2011; 71(6):917-920. PubMed
Keep reading about Acetaminophen And Codeine
Keep reading about Imatinib
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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