CONTRAINDICATIONS
Ondansetron HCl injection, injection premixed, tablets, and oral solution are
contraindicated for patients known to have hypersensitivity to the drug.
WARNINGS
Hypersensitivity reactions have been reported in patients who have exhibited
hypersensitivity to other selective 5–HT3 receptor antagonists.
PRECAUTIONS
Ondansetron is not a drug that stimulates gastric or intestinal peristalsis. It should not be
used instead of nasogastric suction. The use of ondansetron in patients following
abdominal surgery or in patients with chemotherapy-induced nausea and vomiting may
mask a progressive ileus and/or gastric distension.
Carcinogenesis, Mutagenesis, and Impairment of Fertility: Carcinogenic effects were
not seen in 2-year studies in rats and mice with oral ondansetron doses up to 10 and 30
mg/kg per day, respectively. Ondansetron was not mutagenic in standard tests for
mutagenicity. Oral administration of ondansetron up to 15 mg/kg per day did not affect
fertility or general reproductive performance of male and female rats.
Pregnancy, Teratogenic Effects, Pregnancy Category B: Reproduction studies have
been performed in pregnant rats and rabbits at IV doses up to 4 mg/kg per day and have
revealed no evidence of impaired fertility or harm to the fetus due to ondansetron. There
are, however, no adequate and well-controlled studies in pregnant women. Because
animal reproduction studies are not always predictive of human response, this drug should
be used during pregnancy only if clearly needed.
Nursing Mothers: Ondansetron is excreted in the breast milk of rats. It is not known
whether ondansetron is excreted in human milk. Because many drugs are excreted in
human milk, caution should be exercised when ondansetron is administered to a nursing
woman.
Pediatric Use: Little information is available about dosage in pediatric patients 2 years of
age (see DOSAGE AND ADMINISTRATION for use in pediatric patients 4-18 years
of age receiving cancer chemotherapy or for use in pediatric patients 2-12 years of age
receiving general anesthesia).
Geriatric Use: Of the total number of subjects enrolled in cancer chemotherapy-induced
and post-operative nausea and vomiting in US- and foreign-controlled clinical trials, 862
were 65 years of age and over. No overall differences in safety or effectiveness were
observed between these subjects and younger subjects, and other reported clinical
experience has not identified differences in responses between the elderly and younger
patients, but greater sensitivity of some older individuals cannot be ruled out. Dosage
adjustment is not needed in patients over the age of 65 (see CLINICAL
PHARMACOLOGY).