5-Fluorouracil (5-FU) and your teeth

5-Fluorouracil is a chemotherapy drug used for colon, breast, gastric, and other cancers, and as a topical treatment for some skin cancers.

5-FU is one of the most common causes of oral mucositis (chemotherapy-induced mouth ulcers and lining breakdown). The mouth is one of the first places the side effects of 5-FU appear, often in the first one to two weeks of treatment. Patients on 5-FU need proactive dental coordination before and during treatment, because severe mucositis is one of the main reasons chemo doses get delayed or reduced.