ZOTREN

What it is

ZOTREN is available as orally disintegrating tablets containing 4 mg and 8 mg ondansetron. The ZOTREN ODT tablet is administered by placing on top of the tongue where it will rapidly disperse, then should be 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 route of administration and dose of ondansetron should be flexible in the range of 8–32 mg a day. The lowest effective dose should be used. For the 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.

Key safety warnings

Ondansetron prolongs the QT interval in a dose-dependent manner. In addition, post-marketing cases of Torsade de Pointes have been reported in patients using ondansetron. Avoid ondansetron 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. 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. Cases of myocardial ischaemia have been reported in patients treated with ondansetron. In some patients, especially in case of intravenous administration, symptoms appeared immediately after administration of ondansetron. 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. Hypersensitivity to any component of the preparation is contraindicated.

Regulatory history

ZOTREN ODT 4 and ZOTREN ODT 8 orally disintegrating tablets were first listed on the ARTG on 18 October 2017.