ONDANSETRON-AFT

What it is

Ondansetron-AFT is an oral liquid solution containing 0.8 mg/mL of ondansetron (as ondansetron hydrochloride dihydrate). It is a clear, colourless solution. Ondansetron is a potent, highly selective 5HT3 receptor antagonist.

Approved indications

— Prevention and treatment of nausea and vomiting induced by cytotoxic therapy and radiotherapy.

Dosing overview

For emetogenic chemotherapy and radiotherapy, two oral doses of 8 mg each at 12 hourly intervals may be given, with the first dose administered 2 hours prior to chemotherapy or radiotherapy. To protect against delayed emesis after the first 24 hours, ondansetron should be continued orally at a dosage of 8 mg twice daily for up to 5 days after a course of treatment. For highly emetogenic chemotherapy, a single oral dose of up to 24 mg ondansetron taken with oral dexamethasone 12 mg may be given 1–2 hours before commencing chemotherapy, followed by oral ondansetron 8 mg 12-hourly for up to 5 days to protect against delayed emesis. In children over the age of 4 years given intravenously at a dose of 5 mg/m² over 15 minutes immediately before chemotherapy, experience is limited but ondansetron was effective and well tolerated, followed by oral therapy at doses of 4 mg twice daily for up to 5 days. In elderly patients aged over 65 years, efficacy and tolerance were similar to that seen in younger adults, with no need to alter dosage or route of administration. For patients with moderate or severe hepatic dysfunction, a total daily dose of 8 mg should not be exceeded, and for optimum clinical effect this total daily dose is recommended to be administered before chemotherapy or radiotherapy.

Key safety warnings

Ondansetron prolongs the QT interval in a dose-dependent manner, and post-marketing cases of Torsade de Pointes have been reported. Ondansetron should be avoided in patients with congenital long QT syndrome. Ondansetron should be administered with caution to patients who have or may develop prolongation of QTc, including those with electrolyte abnormalities, congestive heart failure, bradyarrhythmias, or those taking other medicinal products that lead to QT prolongation or electrolyte abnormalities. Hypokalemia and hypomagnesemia should be corrected prior to ondansetron administration. Serotonin syndrome has been described following concomitant use of ondansetron and other serotonergic drugs. If concomitant treatment is clinically warranted, appropriate observation of the patient is advised. Cases of myocardial ischaemia have been reported in patients treated with ondansetron, with symptoms sometimes appearing immediately after administration, especially in cases of intravenous administration. Patients should be alerted to the signs and symptoms of myocardial ischaemia.

Contraindications

Based on reports of profound hypotension and loss of consciousness when ondansetron was administered with apomorphine hydrochloride, concomitant use with apomorphine is contraindicated. Hypersensitivity to any component of the preparation is also contraindicated.

Regulatory history

Ondansetron-AFT oral liquid solution (4 mg/5 mL) was first listed on the ARTG on 7 May 2025. The date of first approval was 7 May 2025.