ONDANSETRON ODT-WGR

What it is

Apo-Ondansetron ODT contains 4 mg or 8 mg ondansetron as the active ingredient in orally disintegrating tablets. The orally disintegrating tablet is administered by placing on top of the tongue where it dissolves within seconds, and is swallowed. 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

The dose of ondansetron should be flexible in the range of 8 to 32 mg a day and the lowest effective dose should be used. For control of chemotherapy or radiotherapy induced emesis or nausea in adults, two oral doses of 8 mg each at 12 hourly intervals may be given, the first dose being 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, 1 to 2 hours before commencing chemotherapy, may be followed by oral ondansetron 8 mg 12-hourly for up to 5 days to protect against delayed emesis. Efficacy and tolerance in patients aged over 65 years was similar to that seen in younger adults indicating no need to alter dosage or route of administration in the elderly. It is recommended that a total daily dose of 8 mg should not be exceeded for patients with moderate or severe hepatic dysfunction.

Key safety warnings

Ondansetron prolongs the QT interval in a dose-dependent manner. Post-marketing cases of Torsade de Pointes have been reported in patients using ondansetron. 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 patients with electrolyte abnormalities, congestive heart failure, bradyarrhythmias or patients 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 the concomitant use of ondansetron and other serotonergic drugs. If concomitant treatment with ondansetron and other serotonergic drugs is clinically warranted, appropriate observation of the patient is advised. As ondansetron is known to increase large bowel transit time, patients with signs of subacute intestinal obstruction should be monitored following administration. Ondansetron orally disintegrating tablets contain aspartame and therefore should be taken with caution in patients with phenylketonuria.

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 contraindicated.

Regulatory history

Apo-Ondansetron ODT (ARTG 292170 and 292173) received initial approval on 24 September 2018. The product information was last revised on 31 August 2020.