Oral chemotherapy's black box for warfarin

Publication Date: 
Tue, 11/08/2011
By: Alere Staff

Xeloda® (capecitabine) is an oral form of chemotherapy covered by Medicare. Capecitabine is FDA (U.S. Food and Drug Administration) approved as an adjunct for metastatic breast cancer and metastatic colorectal cancer. Serious interactions have been observed for patients receiving capecitabine and warfarin.

Interactions with Anticoagulants

Capecitabine carries with it a black box warning for patients taking warfarin. Significant increases in PT/INR readings have been observed. Reductions by as much as 85% of thepatients maintenance dose have been observed.1

A case study was presented in the July issue of The Annals of Pharmacotherapy providing details of a 59-year old mechanical heart valve warfarin patient receiving Capecitabine. The authors report the patient received 3 cycles of Capecitabine. There was a weekly dose reduction of greater than 85% to achieve the clinical outcome needed.2

The authors concluded that careful titration of warfarin and frequent monitoring is necessary for the proper use of the two drugs concomitantly.

As always, discuss all medications with your doctor.

  1. Genentech, Inc. Medication Guide for Xeloda tablets [Package Insert]. 2008. San Francisco, CA: Genentech, Inc.
  2. Janney, L, Waterbury, N. Capecitabine-warfarin interaction. Ann Pharmacother. 2005 Sep;39(9):1546-51. Epub 2005 Jul 12.