The common side effects of 5-FU chemotherapy include nausea, diarrhea, mouth sores, eye problems, taste changes and low blood counts, according to Chemocare. The side effects vary from patient to patient, including their onset, length and severity. Other common side effects are a poor appetite and discoloration of the vein where the medication is inserted.
Less common side affects of 5-FU chemotherapy include skin problems, hair thinning, nail changes, and hand-foot syndrome, maintains Chemocare. Hand-foot syndrome is a condition in which the skin on the palms of the hands and the soles of the feet reddens, swells and peels. Possible eye problems are watery eyes or a sensitivity to light. Associated skin changes include dry, cracking skin and darkened areas, especially at sites where previous radiation treatment took place. Associated nail changes include discoloration and in rare cases loss of nails.
Possible rare, serious side effects include chest pain, increased cardiac enzymes and electrocardiogram changes, states Chemocare. Serious adverse reactions may require a reduction or change in the chemotherapy medication. Patients with a history of heart disease are more likely to experience cardiac-related side affects.
Doctors administer 5-FU chemotherapy intravenously to treat colon-rectal cancer, breast cancer, gastrointestinal cancers, head and neck cancers, and ovarian cancer, reports Chemocare. A topical application of 5-FU chemotherapy treats some types of skin cancer.