Known brand names include No current brand name; marketed as generic ondansetron tablets and injection (the original brand was Zofran).
An antiemetic that blocks serotonin 5-HT3 receptors. It prevents nausea and vomiting from cancer chemotherapy, radiation therapy, and surgery. It comes as tablets and as an IV or IM injection.
Labeled use. Prevention with highly or moderately emetogenic chemotherapy, including high-dose cisplatin.
Labeled use. Tablets, for total body irradiation or abdominal radiotherapy.
Sources: [1]
Ondansetron is a first-line choice to prevent chemotherapy, radiation, and postoperative nausea and vomiting, and it avoids the extrapyramidal effects and sedation of dopamine antagonists such as metoclopramide or prochlorperazine. For highly emetogenic chemotherapy it is usually combined with dexamethasone and an NK1 antagonist. Choose another agent with congenital long QT or uncorrected electrolyte problems.
The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug.
Sources: [1]
Doses come from the FDA label. Study tool, not for clinical decisions.
None for any degree of renal impairment, although clearance is lower when creatinine clearance is below 30 mL/min.
None on the current tablet or injection labels. QT prolongation and serotonin syndrome are labeled warnings instead.
No specific antidote; give supportive care. Very large IV doses have been given by mistake without major harm. Overdose has caused hypotension, brief blindness, and heart block, and serotonin syndrome in young children who swallowed tablets.
Sources: [1]
Studies of birth defects, including oral clefts and cardiac defects, have shown inconsistent results with important limitations, so safety in pregnancy cannot be concluded. Postmarketing data have not shown a risk of miscarriage. Animal studies showed no fetal harm.
Present at low levels in breast milk; the relative infant dose was low (3.7%) and no infant adverse effects were reported. Unlikely to cause clinically relevant infant exposure at IV doses up to 4 mg per day.
Oral, moderately emetogenic chemotherapy: ages 12 to 17 use the adult dose; ages 4 to 11, 4 mg 30 minutes before chemotherapy, again 4 and 8 hours later, then 4 mg three times daily for 1 to 2 days. IV chemotherapy prevention from 6 months: 0.15 mg/kg per dose. IV postoperative from 1 month: 0.1 mg/kg if 40 kg or less, 4 mg if over 40 kg. Monitor infants under 4 months closely; clearance is slower.