Drug Interaction Report

Acetaminophen and Imatinib: Interaction Details

A pharmacist-reviewed analysis of the Acetaminophen and Imatinib interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Imatinib

Gleevec Imkeldi
+

Acetaminophen

Acephen Actamin® Anacin AF Bactimicina Cetafen Comtrex Sore Throat Relief CounterAct Pain Feverall
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Jul 10, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 33 documented Acetaminophen interactions, 11 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Major

What happens

Increased acetaminophen levels

Interaction Deep Dive

Concomitant use of chronic doses of acetaminophen with imatinib may result in increased acetaminophen levels and hepatoxicity due to inhibition of UGT-mediated metabolism of acetaminophen by imatinib. In an in-vitro pharmacokinetic study, 200 mg daily doses of imatinib coadministered with acetaminophen is predicted to result in a 22% increase in acetaminophen AUC2. In a case report, fatal acute liver failure occurred in a 51-year old women with chronic myeloid leukemia treated with imatinib 400 mg/day and taking chronic daily acetaminophen doses of 500 to 1000 mg. Carefully monitor liver function tests during treatment and discontinue therapy if elevation of liver function tests occurs 1 due to the possibility of hepatoxicity when acetaminophen is used chronically in a patient receiving imatinib.

Why it happens (mechanism)

Inhibition of UGT-mediated metabolism of acetaminophen by imatinib

Literature reports

1 report — tap to read

a) Fatal acute liver failure was reported in a 51-year old women with chronic myeloid leukemia treated with imatinib 400 mg/day and taking chronic daily acetaminophen doses of 500 to 1000 mg. Following 5 months of imatinib treatment, the patient developed asthenia and began taking acetaminophen. She presented with elevated aminotransferases and a normal bilirubin. Despite discontinuation of imatinib therapy, liver function tests worsened and jaundice and severe hepatitis with coagulopathy (prothrombin time 30% and clotting factor V level 19%) developed. Ultrasound revealed a reduced-size, homogenous liver. Viral and autoimmune hepatitis screening was negative. The patient continued to deteriorate with increased bilirubin, marked decrease of clotting factor V, and grade 3 encephalopathy and expired following cardiac arrest 1.

Common questions

Can I take Acetaminophen and Imatinib together?

Increased acetaminophen levels Always confirm with your pharmacist or prescriber before making any change.

How serious is the Acetaminophen 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 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 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 (2)

  1. Ridruejo E, Cacchione R, Villamil AG, et al: Imatinib-induced fatal acute liver failure. World J Gastroenterol 2007; 13(48):6608-111. PubMed
  2. Liu Y, Ramirez J, & Ratain MJ: Inhibition of paracetamol glucuronidation by tyrosine kinase inhibitors. Br J Clin Pharmacol 2011; 71(6):917-920. DOI
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Imatinib

Keep reading about Imatinib

All Imatinib interactions (79)
Also serious with: Lefamulin Neratinib Finerenone Olaparib
Acetaminophen

Keep reading about Acetaminophen

All Acetaminophen interactions (33) Acetaminophen drug information
Also serious with: Articaine Carbamazepine Exenatide Flucloxacillin
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Imatinib + Activated Charcoal American Hellebore Arsenic Cesium Ephedra Grapefruit Sida Cordifolia St. John's Wort + 145 more
Acetaminophen + Activated Charcoal Asarabacca Beer Siberian Cocklebur Wine Adrafinil African Wild Potato Aristolochia + 147 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.