Composition
Inj 4 mg/8 mg: Per ml: Ondansetron 2 mg; 4 mg(2 ml)/8 mg(4 ml); soln in amp. Tab 4 mg/8 mg: Ondansetron 4 mg/8 mg. Syp: Per 5 ml: Ondansetron 4 mg.
Indications & Dosage
Moderately emetogenic chemotherapy or radiotherapy: ORAL: Adult: 8 mg, 1-2 hours before treatment, then 8 mg every 12 hrs for up to 5 days. BY RECTUM: Adult: 16 mg, 1-2 hours before treatment, then 16 mg daily for up to 5 days. BY IM INJ, OR BY SLOWIV INJ: Adult: 8 mg, immediately before treatment, then (oral) 8 mg every 12 hours for up to 5 days, alternatively (by rectum) 16 mg daily for up to 5 days. BY IM INJ, OR BY IV INF: Elderly: 8 mg, immediately before treatment, IV INF to be given over at least 15 minutes, then (oral) 8 mg every 12 hours for up to 5 days, alternatively (by rectum) 16 mg daily for up to 5 days Severely emetogenic chemotherapy: ORAL: Adult: 24 mg, dose to be taken 1-2 hours before treatment, then 8 mg every 12 hours for up to 5 days BY RECTUM: Adult: 16 mg, dose to be administered 1-2 hours before treatment, then 16 mg daily for up to 5 days BY IM INJ, OR BY SLOWIV INJ: Adult: 8 mg, dose to be administered immediately before treatment, followed by (by IM inj or by slow IV inj) 8 mg every 4 hours if required for 2 doses, alternatively, followed by (by continuous IV INF) 1 mg/hour for up to 24 hours, then (oral) 8 mg every 12 hours for up to 5 days, alternatively (by rectum) 16 mg daily for up to 5 days. Children 6 months-18 yrs: By IV INF over at least 15 minutes, 150 mcg/kg immediately before chemotherapy (max single dose 8 mg) repeated every 4 hr for 2 further doses, then give by mouth; max total daily dose 32mg. Oral dosing can start 12 hr after IV administration; for bodyweight 10 kg or less, 2 mg every 12 hr for up to 5 days (max total daily dose 32 mg); body-weight over 10 kg, 4 mg every 12 hr for up to 5 days (max total daily dose 32 mg); bodyweight over 40 kg, 8 mg every 12 hr for up to 5 days (max total daily dose 32 mg). Prevention and treatment of postoperative nausea and vomiting: ORAL: Adult: 16 mg, dose to be taken 1 hour before anaesthesia, BY IM INJ OR BY SLOW IV INJ: Adult: 4 mg, dose to be administered at induction of anaesthesia Children 1 months-18 yrs: 100 mcg/kg (max 4 mg) as a single dose by slow IV injection over at least 30 sec, before, during, or after induction of anaesthesia.
Administration
IM: Should be given undiluted. IV: Give first dose 30 min prior to beginning chemotherapy; the IV preparation has been successful when administered orally. IVPB: Infuse over 15-30 min; 24-hour continuous infusions have been reported, but are rarely used. RECONSTITUTION: Prior to IV infusion, dilute in 50-100 ml D5W or NS.
Compatibility
Stable in D5 1/2 NS, D5NS, DSW, mannitol10%, LR, NS, NS 3%. do not mix injection with alkaline solutions. Y-site administration: See drug to drug compatibility and incompatibility chart.
Stability
Store vials between 2C-30C. Protect from light. Stable when mixed in 5% dextrose or 0.9% NaCI for 48 hours at room temperature.
Precautions
Hepatic impairment, adenotonsillar surgery, sub acute intestinal obstruction, susceptibility to QT-interval prolongation(including electrolyte disturbances).
Interactions
Tramadol, Phenytoin, rifampicin, carbamazepine,
Pregnancy
Caution advised
Lactation
Caution advised
Side Effects
Constipation, headache, flushing, arrhythmias, bradycardia, chest pain, hiccups, hypotension, movement disorders, seizure, transient rise in liver enzymes, ST segment depression, extra-pyramidal reactions, visual disturbance.