ONDANSETRON-Baxter

What it is

Ondansetron-Baxter is ondansetron hydrochloride dihydrate at a concentration of 2 mg/mL. It is supplied as a solution for injection for intramuscular or intravenous use.

Approved indications

— Prevention and treatment of nausea and vomiting induced by cytotoxic therapy and radiotherapy — Prevention and treatment of post-operative nausea and vomiting

Dosing overview

The route of administration and dose should be flexible in the range of 8–32 mg per day. The lowest effective dose should be used. Dosing varies by indication and patient population:

Intravenous doses greater than 8 mg should be given by slow intravenous infusion over at least 15 minutes, since rapid intravenous administration has been associated with a higher incidence of transient visual disturbances. A single dose greater than 16 mg should not be given.

Key safety warnings

Ondansetron prolongs the QT interval in a dose-dependent manner, and 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 and administered with caution to patients who have or may develop prolongation of QTc, including those with electrolyte abnormalities, congestive heart failure, bradyarrhythmias, or patients taking other medicines that lead to QT prolongation or electrolyte abnormalities. Hypokalaemia and hypomagnesaemia should be corrected prior to ondansetron administration. Serotonin syndrome has been described following concomitant use of ondansetron and other serotonergic drugs, and appropriate observation of the patient is advised if concomitant treatment is clinically warranted. Cases of myocardial ischaemia have been reported in patients treated with ondansetron, with symptoms sometimes appearing immediately after administration, particularly with intravenous use. Patients should be alerted to the signs and symptoms of myocardial ischaemia. As ondansetron is known to increase large bowel transit time, patients with signs of subacute intestinal obstruction should be monitored following administration.

Contraindications

Based on reports of profound hypotension and loss of consciousness when ondansetron was administered with apomorphine hydrochloride, concomitant use with apomorphine is contraindicated. Ondansetron-Baxter is contraindicated in patients with hypersensitivity to any component of the preparation.

Regulatory history

Ondansetron-Baxter was first listed on the Australian Register of Therapeutic Goods on 7 May 2009, with two registered variants: 4 mg/2 mL solution for injection (ARTG 147103) and 8 mg/4 mL solution for injection (ARTG 155610).