Fluorouracil & Fluorouracil Prodrugs/Allopurinol 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:

Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Allopurinol may change how your your body breaks down capecitabine, fluorouracil, or tegafur.

What might happen:

The amount of capecitabine, fluorouracil, and tegafur in your body may decrease. Your cancer medicine may not work as well.

What you should do about this interaction:

Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Let your healthcare professional know if your condition does not improve or worsens. Your doctor may need to change one or both of your medicines.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.Xeloda (capecitabine) US prescribing information. Roche Pharmaceuticals December, 2022.
  • 2.Xeloda (capecitabine) UK Summary of Product Characteristics. Roche Products Limited April, 2019.
  • 3.Teysuno (tegafur/gimeracil/oteracil) UK summary of product characteristics. Nordic Group B.V. February, 2022.
  • 4.Uftoral (tegafur/uracil) UK summary of product characteristics. Merck Pharmaceuticals March 9, 2006.

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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.