Moderate to severe reaction on your first or second round of 5-FU (Fluorouracil) or Capecitabine (Xeloda)

Moderate to severe reaction on your first or second round of 5-FU (Fluorouracil) or Capecitabine

While it is common for side effects to occur to a mild or moderate degree with 5-FU (Fluorouracil), or Capecitabine (Xeloda), if you think that you are having a moderate to severe reaction on your first or second round of chemotherapy, you should contact your healthcare provider immediately. Unmanaged, early-onset severe toxicities can result in acute respiratory distress syndrome, and sepsis leading to multisystem organ failure, septic shock and death. Be sure to speak to your doctor about these risks prior to starting treatment.

Why Get Tested First?

Approximately 5-7% of patients carry genetic DPYD variants that can lead to much greater risk of severe toxic reactions or death.

For every 1000 patients treated with these drugs, approximately 10 will die from severe toxicity.1

Warning Signs Of Severe Toxicity (Grade 3 Or 4):

According to the Colon Cancer Alliance (CCA), the following symptoms can be signs of a life-threatening toxicity especially if they occur during the first or second round of treatment.

TALK TO YOUR HEALTH CARE PROVIDER IMMEDIATELY if you think you are experiencing these symptoms as it is critical that you receive treatment as soon as possible.

  • Diarrhea more than 7 times what is normal for you and/or incontinence
  • Mucositis- oral and/or anal that interferes with eating, drinking, swallowing or daily activities
  • Nausea to the point where you are unable to eat or drink
  • Vomiting more than than 6 times

  • Bleeding (hemorrhage), including black tarry stools or “coffee ground” vomit

  • Severe hand and foot syndrome, including pain, blisters, bleeding and peeling that interferes with daily activities

  • Cardiac arrhythmias (irregular heart beats), chest pain or heart attack, acute pulmonary edema, congestive heart failure, cardiac arrest

  • Neurologic cerebellar syndrome (uncoordination), dizziness, queasiness, disorientation, seizures, coma

AUDT recommends that you also speak to your healthcare provider immediately if you experience any severe or worsening of the common “side effects”, as deadly toxicities do not always present the same in each patient.

The only approved antidote for life-threatening toxicities is Uridine triacetate (Vistogard®) which must be given within 96 hours of your last dose of 5-FU or Xeloda to reduce or prevent further toxicity from developing.

For more information, see the full “5-FU & XELODA: Side Effects vs. Symptoms” fact sheet at:

Further information on side effects vs. severe toxicities can be found here:

Faces of True Cost of Toxicity

This video, while listed on the Vistogard website, does not represent uses of Vistogard, the FDA approved antidote to 5-FU toxicity. Why? These individuals were not diagnosed with 5-FU toxicity until after the 96 hour window when Vistogard must be administered. The Faces of True Cost of Toxicity video is the experience of: an oncologist who witnessed 5-FU toxicity, two individuals who lost a loved one to 5-FU toxicity and one patient who herself had severe toxic reactions to 5-FU. After watching this video, most individuals will be shocked that testing for DPD Deficiency before administration of 5-FU/Capecitabine is not standard of care in the United States. While no one disagrees that this is a key chemotherapy drug for most people, however, for some, it is life ending.

Working with Your Oncologist

Working with Your Oncologist

You will need to initiate discussion of testing for DPD/DPYD deficiency with your oncologist because it is NOT the standard of care in the US.