Nausea and vomiting shall be prevented. Most effective prevention and treatment is obtained by various modifications of 5-HT₃ receptor blockers. Sometimes merely changes of eating habits are of great value. Relaxing measures can reduce nausea and vomiting particularly in patients where the symptoms are conditioned. Acupressure and acupuncture have also been reported to be beneficial. Careful hygiene of the oral cavity, e.g. by regular rinsing, is of value to prevent stomatitis. Cryotherapy during 30 min before chemotherapy is reported to decrease the mucositis.

Fluorouracil. Fluorouracil is a common cause of nausea and vomiting (1/10–1/100 of treated patients). This drug can also cause cerebral ataxia (1/10–1/100), confusion or nystagmus (1/1,000–1/10,000). It is stated that alopecia occurs after treatment with fluorouracil in 1/10–1/100 patients. Fluorouracil causes stomatitis in 40–60 % (1/10–1/100) which often is the first sign of toxicity, and it will cause leucopenia quite often (1/10–1/100). It is sometimes associated with changes in ECG (1/10–1/100) but more seldom with arrhythmia and coronary angina (1/100–1/1,000) or heart failure/myocardial infarction (1/1,000–1/10,000). Increased secretion of tears, pathological visual changes, or hypersensitivity for light is reported after treatment with fluorouracil (1/1,000–1/10,000).