Ondansetron Dosage

Medically reviewed by Drugs.com. Last updated on Aug 4, 2023.

Usual Adult Dose for Nausea/Vomiting - Chemotherapy Induced

Oral:
Highly Emetogenic Cancer Chemotherapy (HEC):

• Recommended dose: 24 mg orally 30 minutes before the start of single-day HEC (including cisplatin doses of 50 mg/m2 or greater)

Moderately Emetogenic Cancer Chemotherapy (MEC):

• Recommended dose: 8 mg orally twice a day, with the first dose administered 30 minutes before the start of chemotherapy and the subsequent dose 8 hours later; then 8 mg orally 2 times a day (every 12 hours) for 1 to 2 days after the completion of chemotherapy

Parenteral:

• Recommended dose: 0.15 mg/kg IV, with the first dose (infused over 15 minutes) 30 minutes before the start of emetogenic chemotherapy and subsequent doses given 4 and 8 hours after the first dose.
• Maximum dose: 16 mg per dose

Comments:

• Multi-day, single-dose administration of 24 mg orally for HEC has not been studied.
• The injection formulation should be diluted prior to IV administration.

Uses:

• Prevention of nausea and vomiting associated with HEC or MEC
• Prevention of nausea and vomiting associated with initial and repeat courses of emetogenic chemotherapy

Usual Adult Dose for Nausea/Vomiting

Oral:
Highly Emetogenic Cancer Chemotherapy (HEC):

• Recommended dose: 24 mg orally 30 minutes before the start of single-day HEC (including cisplatin doses of 50 mg/m2 or greater)

Moderately Emetogenic Cancer Chemotherapy (MEC):

• Recommended dose: 8 mg orally twice a day, with the first dose administered 30 minutes before the start of chemotherapy and the subsequent dose 8 hours later; then 8 mg orally 2 times a day (every 12 hours) for 1 to 2 days after the completion of chemotherapy

Parenteral:

• Recommended dose: 0.15 mg/kg IV, with the first dose (infused over 15 minutes) 30 minutes before the start of emetogenic chemotherapy and subsequent doses given 4 and 8 hours after the first dose.
• Maximum dose: 16 mg per dose

Comments:

• Multi-day, single-dose administration of 24 mg orally for HEC has not been studied.
• The injection formulation should be diluted prior to IV administration.

Uses:

• Prevention of nausea and vomiting associated with HEC or MEC
• Prevention of nausea and vomiting associated with initial and repeat courses of emetogenic chemotherapy

Usual Adult Dose for Nausea/Vomiting - Postoperative

Oral:

• Recommended dose: 16 mg orally 1 hour before the induction of anesthesia

Parenteral:

• Recommended dose: 4 mg IV (undiluted) immediately before induction of anesthesia or postoperatively (nausea and/or vomiting within 2 hours after surgery)
• Alternative route: 4 mg IM (undiluted)

Comment:

• Administration of a second dose does not provide additional control of nausea and vomiting.

Use:

• Prevention of postoperative nausea and vomiting

Usual Adult Dose for Nausea/Vomiting - Radiation Induced

Recommended dose: 8 mg orally 3 times a day

• Total Body Irradiation: 8 mg orally 1 to 2 hours before each fraction of radiotherapy administered each day
• Single High-dose Fraction Radiotherapy to the Abdomen: 8 mg orally 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for 1 to 2 days after the completion of radiotherapy
• Daily Fractionated Radiotherapy to the Abdomen: 8 mg orally 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for each day radiotherapy is given

Use:

• Prevention of nausea and vomiting associated with radiotherapy, either as total body irradiation, single high-dose fraction, or daily fractions to the abdomen

Usual Pediatric Dose for Nausea/Vomiting - Postoperative

Parenteral:
1 month to 12 years:
Less than 40 kg:

• Recommended dose: 0.1 mg/kg IV over 2 to 5 minutes immediately prior to/following anesthesia induction or postoperatively (nausea and/or vomiting occurring shortly after surgery)

40 kg and greater:

• Recommended dose: 4 mg IV over 2 to 5 minutes immediately prior to/following anesthesia induction or postoperatively (nausea and/or vomiting occurring shortly after surgery)

Use:

• Prevention of postoperative nausea and vomiting

Usual Pediatric Dose for Nausea/Vomiting - Chemotherapy Induced

Oral:
4 to 11 years:

• Recommended dose: 4 mg orally 3 times a day, with the first dose administered 30 minutes before the start of chemotherapy, and subsequent doses 4 and 8 hours after the first dose; then 4 mg orally 3 times a day (every 8 hours) for 1 to 2 days after the completion of chemotherapy

12 years and older:

• Recommended dose: 8 mg orally twice a day, with the first dose administered 30 minutes before the start of chemotherapy and the subsequent dose 8 hours later; then 8 mg orally 2 times a day (every 12 hours) for 1 to 2 days after the completion of chemotherapy

Parenteral:
6 months to 18 years:

• Recommended dose: 0.15 mg/kg IV, with the first dose (infused over 15 minutes) 30 minutes before the start of emetogenic chemotherapy, and subsequent doses given 4 and 8 hours after the first dose
• Maximum dose: 16 mg (per dose)

Comments:

• The injection formulation should be diluted in 50 mL prior to IV administration.
• This drug should be used to prevent nausea and vomiting associated with moderately to highly emetogenic chemotherapy.

Uses:

• Prevention of nausea and vomiting associated with moderately emetogenic cancer chemotherapy
• Prevention of nausea and vomiting associated with initial and repeat courses of emetogenic chemotherapy

Renal Dose Adjustments

No adjustment recommended.

Liver Dose Adjustments

• Mild to moderate hepatic impairment (Child-Pugh less than 10): No adjustment recommended.
• Severe hepatic impairment: (Child-Pugh 10 or greater): 8 mg IV over 30 minutes before the start of emetogenic chemotherapy; maximum 8 mg per day

Precautions

Safety and efficacy have not been established in patients younger than 6 months (parenteral formulations) and 4 years (oral formulations).

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• Do not push oral dissolving tablets (ODTs) through the foil backing.
• ODT and film formulations should be used with dry hands and immediately placed on the tongue. The dosage form should dissolve in saliva. Administration with additional liquid is not necessary. In patients requiring multiple films per dose, each film should be allowed to completely dissolve before administering the next film.
• IV doses greater than 8 mg should be slowly injected over at least 15 minutes. Single IV doses greater than 16 mg should be avoided.
• IM doses should be administered undiluted at a rate slower than 30 seconds (e.g., 2 to 5 minutes).
• The suppository formulation is not recommended for use in children.

Storage requirements:

• The manufacturer product information should be consulted.

Reconstitution/preparation techniques:

• The manufacturer product information should be consulted.

IV compatibility:

• The manufacturer product information should be consulted.

General:

• The lowest effective dose should be used.
• Oral, rectal, IV, and IM routes have shown to be equally effective over the first 24 hours of chemotherapy.
• Use of the ODT formulation in the prevention of nausea and vomiting associated with highly-emetogenic chemotherapy, radiotherapy, or in postoperative situations has not been studied in pediatric patients.
• Concomitant use with dexamethasone may potentiate the antiemetic effects of this drug.
• Routine prophylaxis is not recommended for postoperative patients with little expectation of nausea and vomiting; however, use is recommended for patients who should avoid postoperative nausea and vomiting, even with low risk of postoperative nausea and vomiting.

Monitoring:

• Electrolyte levels, especially in patients at risk for hypomagnesemia or hypokalemia
• ECG, especially in patients with a history of QT prolongation, bradycardia, congestive heart failure, or those on drugs which could prolong the QT interval or result in electrolyte abnormalities
• Signs/symptoms of respiratory events or hypersensitivity reactions

Patient advice:

• Inform patients that this drug may cause drowsiness, and they should avoid driving or operating machinery until the full effects of the drug are seen.
• Patients should be advised to immediately report any signs/symptoms associated with serotonin syndrome or hypersensitivity reactions to their prescribers. Patients should also report lightheadedness, syncope episodes, or any perceived changes in heart rate.
• Advise patients to speak to their healthcare provider if they become pregnant, intend to become pregnant, or are breastfeeding.
• Tell patients to report all concurrent prescription and nonprescription medications or herbal products they are taking.

Frequently asked questions

• Can you take ondansetron while pregnant?

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer