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    DEA Class; Rx

    Common Brand Names; Zofran, Zofran ODT, Zuplenz

    • Antiemetics, Selective 5-HT3 Antagonist

    Antiemetic; 5-HT3 receptor antagonist
    Used for prevention and treatment of nausea and vomiting due to chemotherapy, radiation therapy and surgery
    Risk of dose-dependent QT prolongation and torsades de pointes

    Indicated for chemotherapy-induced nausea/vomiting prophylaxis (CINV prophylaxis) and radiation-induced nausea/vomiting prophylaxis (RINV prophylaxis).
    For post-operative nausea/vomiting (PONV) prophylaxis.
    For the treatment of post-operative nausea/vomiting (PONV).
    For the treatment of pregnancy-induced nausea/vomiting.
    For the short-term treatment of nausea/vomiting associated with acute gastroenteritis.
    For the treatment of pruritus secondary to cholestasis.
    For the maintenance treatment of alcohol dependence.
    For the treatment of cyclic vomiting syndrome.


    Coadministration with apomorphine; combination reported to cause profound hypotension and loss of consciousness

    • Headache (9-27%)
    • Malaise/fatigue (9-13%)
    • Constipation (6-11%)
    • Hypoxia (9%)
    • Drowsiness (8%)
    • Diarrhea (2-7%)
    • Dizziness (7%)
    • Fever (2-8%)
    • Gynecologic disorder (7%)
    • Anxiety (6%)
    • Urinary retention (5%)
    • Pruritus (2-5%)
    • Injection-site pain (4%)
    • Paresthesia (2%)
    • Cold sensation (2%)
    • Elevated liver function test results (1-5%)

    Hypersensitivity reactions including anaphylaxis and bronchospasm may occur: discontinue therapy if suspected; monitor and treat promptly per standard of care until signs and symptoms resolve

    Reduce dose with severe hepatic impairment

    Use according to schedule, not PRN

    Do not use instead of nasogastric suction

    Ondansetron may mask progressive ileus or gastric distention in patients who are undergoing abdominal surgery or experiencing chemotherapy-induced nausea and vomiting; monitor for decreased bowel activity, particularly in patients with risk factors for gastrointestinal obstruction

    Ondansetron is not a drug that stimulates gastric or intestinal peristalsis; should not be used instead of nasogastric suction

    Serotonin syndrome reported with 5-HT3 receptor antagonists alone but particularly with concomitant use of serotonergic drugs including SSRIs, SNRIs, MAO inhibitors, lithium, tramadol, methylene blue IV, and mirtazapine; if concomitant use with other serotonergic drugs is clinically warranted, patients should be made aware of potential increased risk for serotonin syndrome

    Cross-sensitivity among selective serotonin antagonists may occur

    Zofran ODT contains phenylalanine (caution for phenylketonurics)

    Dose-dependent QT prolongation; avoid in patients with congenital long QT syndrome; ECG monitoring recommended in patients who have electrolyte abnormalities, CHF, or bradyarrhythmias or who are also receiving other medications that cause QT prolongation

    Published epidemiological studies on association between ondansetron use and major birth defects have reported inconsistent findings and have important methodological limitations that preclude conclusions about safety use in pregnancy

    Not known whether ondansetron is present in human milk; there are no data on effects of therapy on breastfed infant or effects on milk production; however, it has been demonstrated that the drug is present in milk of rats; when a drug is present in animal milk, it is likely that the drug will be present in human milk


    24 mg/day PO; 0.45 mg/kg/day IV (in 3 divided doses, max single dose = 16 mg IV).


    24 mg/day PO; 0.45 mg/kg/day IV (in 3 divided doses, max single dose = 16 mg IV).


    0.15 mg/kg/dose IV (Max: 16 mg/dose IV). 16 mg/day PO.


    < 4 years: 0.15 mg/kg/dose IV (Max: 16 mg/dose). Safety and efficacy have not been established for PO formulation.
    4—11 years: 0.15 mg/kg/dose IV (Max: 16 mg/dose). 12 mg/day PO.
    >= 12 years: 0.15 mg/kg/dose IV (Max: 16 mg/dose). 16 mg/day PO.


    1—5 months: 0.1 mg/kg IV (single dose). Safety and efficacy have not been established for PO formulation.
    >= 6 months: 0.15 mg/kg/dose IV (Max: 16 mg/dose IV). Safety and efficacy have not been established for PO formulation.


    Safety and efficacy have not been established.

    Ondansetron hydrochloride

    injectable solution

    • 2mg/mL


    • 4mg
    • 8mg
    • 24mg

    oral solution

    • 4mg/5mL

    oral soluble film

    • 4mg
    • 8mg

    orally disintegrating tablets

    • 4mg
    • 8mg