ondansetron

Ondansetron is an anti-nausea medication most often used to prevent nausea and vomiting caused by chemotherapy. Chemotherapy agents increase secretion of serotonin which stimulates serotonin (5-HT3) receptors in the brain, causing nausea and vomiting. Ondansetron works by selectively blocking serotonin (5-HT3) receptors, reducing the effect of increased serotonin due to chemotherapy. The FDA approved ondansetron in December 1992.

Zofran, Zofran ODT, Zuplenz

GENERIC AVAILABLE: Yes

Yes

Side effects of ondansetron are

• headache,
• malaise,
• fatigue,
• drowsiness,
• constipation,
• dizziness, and
• diarrhea.

Some individuals may develop abnormal heart rate and rhythm.

Dosing for adults

• Highly nauseating chemotherapy: 24 mg orally dissolved on tongue 30 minute prior to start of a single-day chemotherapy.
• Moderately nauseating chemotherapy: Take 8 mg tablet 30 minute prior to chemotherapy and repeated in 8 hours, then 8 mg every 12 hours for 1 to 2 days after chemotherapy.
• Radiation-induced nausea and vomiting: Take 8 mg orally 1 to 2 hours prior to radiation and every 8 hours after first dose, as needed.
• Post-surgery nausea and vomiting: 16 mg orally 1 hour before anesthesia.

Dosing for children

• Moderately nauseating chemotherapy (12 years and older) : 8 mg orally prior to chemotherapy and repeated in 8 hours, then 8 mg every 12 hours for 1 to 2 days after chemotherapy.
• Moderately nauseating chemotherapy (4 to 11 years): 4 mg orally 30 minute prior to chemotherapy and repeated in 4 and 8 hours after the first dose, then every 8 hours for 1 to 2 days after chemotherapy.
• Not recommended for children under 4 years old.

: Ondansetron and apomorphine should not be used together due to sudden lowering in blood pressure and loss of consciousness.

Phenytoin, carbamazepine, and rifampin can increase ondansetron elimination and decrease blood levels, possibly lowering the effects of ondansetron.

Dronedarone can increase blood levels of ondansetron by reducing its breakdown in the liver. This may increase side effects of ondansetron. This combination may also increase the risk of abnormal heart beats.

There are no adequate studies of ondansetron in pregnant women to determine its safe and effective use during pregnancy.

It is not known whether ondansetron enters breast milk; therefore, it is best to be cautious before using it in nursing mothers.

What preparations of ondansetron oral disintegrating tablet are available?

Tablets (ODT): 4, 8 mg; Oral Film: 4, 8 mg; Tablet: 4, 8, 24 mg; Solution: 4 mg/5 ml. Injectable; 2 mg/ml

How should I keep ondansetron oral disintegrating tablet stored?

Store ondansetron between 2 C and 30 C (36 and 86 F).