Irinotecan/Strong CYP3A4 Inhibitors Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Very Serious. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Your medicine may slow down how quickly your liver processes irinotecan.

What might happen:

The amount of irinotecan in your blood may increase. This may cause you to have more side effects from your medicine. Possible side effects include but are not limited to diarrhea, difficulty sleeping, dizziness, fever, rash, or vomiting.

What you should do about this interaction:

Let your healthcare professional (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want to check the amount of irinotecan in your blood or change the amount of irinotecan you take. If you notice any new side effects from your irinotecan, or if any side effects become worse, contact your health care professionals right away.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Santos A, Zanetta S, Cresteil T, Deroussent A, Pein F, Raymond E, Vernillet L, Risse ML, Boige V, Gouyette A, Vassal G. Metabolism of irinotecan (CPT-11) by CYP3A4 and CYP3A5 in humans. Clin Cancer Res 2000 May;6(5):2012-20.
  • 2.Kehrer DF, Mathijssen RH, Verweij J, de Bruijn P, Sparreboom A. Modulation of irinotecan metabolism by ketoconazole. J Clin Oncol 2002 Jul 15; 20(14):3122-9.
  • 3.Camptosar (irinotecan hydrochloride) US prescribing information. Pharmacia & Upjohn Company January, 2020.
  • 4.Nizoral (ketoconazole oral) US prescribing information. Janssen Pharmaceuticals February, 2014.
  • 5.Corona G, Vaccher E, Sandron S, Sartor I, Tirelli U, Innocenti F, Toffoli G. Lopinavir-ritonavir dramatically affects the pharmacokinetics of irinotecan in HIV patients with Kaposi's sarcoma. Clin Pharmacol Ther 2008 Apr;83(4):601-6.
  • 6.This information is based on an extract from the Certara Drug Interaction Database (DIDB) Platform, Copyright Certara 1999-2023..
  • 7.Phansalkar S, Desai AA, Bell D, Yoshida E, Doole J, Czochanski M, Middleton B, Bates DW. High-priority drug-drug interactions for use in electronic health records. J Am Med Inform Assoc 2012 Sep-Oct; 19(5):735-43.
  • 8.Sporanox (itraconazole) US prescribing information. Janssen Pharmaceutica Products, L.P. February, 2024.

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.