Managing Chemotoxicity

Side Effects of 5-FU Chemotherapy

As you are aware, some patients on 5-FU can experience severe dose limiting toxicities.

These complications include neutropenia, diarrhea, hand-foot syndrome, stomatitis, mucositis and myelosuppression.  These toxicities can have significant effects on treatment time and cost including:

  • Dose reductions
  • Treatment delays
  • Changes in or discontinuation of therapy
  • Extra interventions to address potentially harmful side effects
    • Fluid- and nutritional-replacement therapies
    • Hematopoietic-stimulating therapies
    • Antibiotics
    • Clinic and hospital visits
  • Patient discomfort and diminished quality of life
  • Hospitalization

TheraGuide® 5-FU — A Test that Predicts 5-FU Toxicity

If you are considering 5-FU-related chemotherapy for a specific patient, the comprehensive TheraGuide 5-FU test can help you evaluate his/her risk for serious side effects. 

One in four patients carries variations in either of two genes, DPYD or TYMS, that will increase their risk of dose limiting adverse events to 5-FU-related therapy. The test requires only a small sample of the patient’s blood, which is sent to Myriad for analysis. Instructions and materials needed for sample collection can be ordered through our Online Order Form.  If you would like more information about TheraGuide 5-FU, please visit