Tablet: Oval, biconvex, yellow film-coated tablets engraved "BIOLAB'' on one face and bisected on the obverse.
Each tablet contains Ondansetron 8 mg.
Injection: Clear, colorless solution.
Each ampoule of 2 ml contains Ondansetron 4 mg.
Each ampoule of 4 ml contains Ondansetron 8 mg.
Pharmacology: Pharmacodynamics: Ondansetron is a potent, highly selective 5HT3 receptor-antagonist. Chemotherapy and radiotherapy may cause release of 5HT in the small intestine initiating a vomiting reflex by activating vagal afferents via 5HT3 receptors. Ondansetron blocks the initiation of this reflex. Activation of vagal afferents may also cause a release of 5HT in the area postrema, located on the floor of the fourth ventricle and this may also promote emesis through a central mechanism. Thus the effect of ondansetron is probably due to antagonism of 5HT3 receptors on neurons located both in the peripheral and central nervous system.
Pharmacokinetics: Onset of effect: Within 30 minutes.
Plasma protein binding: 70% to 76%.
Metabolism: Extensively in the liver by hydroxylation, followed by glucuronide or sulfate conjugation.
Bioavailability: Oral: 56%.
Half-life: Children <15 years: 2-3 hours, adults: 3-6 hours.
Time to peak: Oral: ~2 hours.
Elimination: In urine and feces; <10% of parent drug recovered unchanged in urine.
Management of nausea and vomiting induced by cytotoxic chemotherapy and radiotherapy.
Prevention and treatment of post-operative nausea and vomiting.
Chemotherapy and radiotherapy induced nausea and vomiting: Adults: The route of administration and dose of ZETRON should be flexible in the range of 8-32 mg a day.
Emetogenic chemotherapy and radiotherapy: 8 mg should be administered as a slow intravenous injection immediately before treatment or 8 mg orally 1-2 hours before treatment, either regimen is followed by 8 mg orally every 12 hours for up to 5 days after a course of treatment to protect against delayed emesis.
Highly emetogenic chemotherapy: Intravenous regimen is recommended. The following dose schedules appear to be equally effective: 1. A single dose of 8 mg by slow intravenous injection immediately before chemotherapy.
2. A dose of 8 mg by slow intravenous injection immediately before chemotherapy, followed by two further intravenous doses of 8 mg 2-4 hours apart.
3. A dose of 8 mg by slow intravenous injection immediately before chemotherapy, followed by a continuous infusion rate of 1 mg/hour for 24 hours.
4. A single dose of 32 mg diluted in 50-100 ml of saline or other compatible infusion fluids (as indicated) and infused over not less than 15 minutes immediately before chemotherapy.
The selection of dose regimen should be determined by the severity of the emetogenic challenge.
The efficacy of Ondansetron will be enhanced by the addition of a single intravenous dose of dexamethasone sodium phosphate 20 mg administered prior to chemotherapy.
To protect against delayed emesis after the first 24 hours, ZETRON should be continued orally, 8 mg twice daily for up to 5 days after a course of treatment.
Children: Dose of 5 mg/m2 body-surface intravenously immediately before chemotherapy, followed by 4 mg orally twice daily for up to 5 days after a course of treatment.
Elderly: ZETRON is well tolerated by patients over 65 years and no alteration of dosage, dosing frequency or route of administration are required.
Post-operative nausea and vomiting: Adults: For prevention of post-operative nausea and vomiting: 4 mg given by intramuscular or slow intravenous injection at the induction of anaesthesia or as a single dose of 16 mg given orally one hour prior to anaesthesia.
For treatment of established post-operative nausea and vomiting: A single dose of 4 mg given by intramuscular or slow intravenous injection is recommended.
Children and elderly: There is limited experience in the use of ondansetron in the prevention and treatment of post-operative nausea and vomiting. Not recommend for children and elderly use.
Patients with hepatic impairment: Clearance of ondansetron is significantly reduced and serum-half-life significantly prolonged in subjects with moderate or severe impairment of hepatic function. A total daily dose of 8 mg should not be exceeded.
Compatibility: ZETRON injection should be admixed with the following infusion fluids and has been shown to be stable for 7 days in a refrigerator: Sodium chloride intravenous infusion BP 0.9% w/v, Glucose intravenous infusion BP 5% w/v, Mannitol intravenous infusion BP 10% w/v, Ringers intravenous infusion, Potassium chloride 0.3% w/v and Sodium chloride 0.9% w/v intravenous infusion BP, Potassium chloride 0.3% w/v and Glucose 5% w/v intravenous infusion BP.
Overdose and Treatment: Sudden transient blindness, severe constipation, hypotension, and vasovagal episode with transient secondary heart block have been reported in some cases of overdose. I.V. doses of up to 252 mg/day have been inadvertently given without adverse effects. There is no specific antidote.
Treatment is symptom-directed and supportive.
Hypersensitivity to ondansetron, other selective 5-HT3 antagonists, or any component of the formulation.
Ondansetron should be used on scheduled basis, not on an "as needed" (PRN) basis, since data supports the use of this drug in the prevention of nausea and vomiting and not in the rescue of nausea and vomiting. Ondansetron should only be used in the first 24-48 hours of receiving chemotherapy. Data does not support any increased efficacy of ondansetron in delayed nausea and vomiting. Does not stimulate gastric or intestinal peristalsis; may mask progressive ileus and/or gastric distension.
In pregnancy: Ondansetron is not teratogenic in animals. It should not be used during pregnancy especially during the first trimester, unless the expected benefit to the patient is thought to outweigh any possible risk to fetus.
In lactation: Ondansetron is excreted in the breast milk of animals. It is therefore recommended that mothers receiving ondansetron should not breast-feed their babies.
>10%: Cardiovascular: Malaise/fatigue.
Central nervous system: Headache.
1% to 10%: Central nervous system: Drowsiness, fever, dizziness, anxiety, cold sensation.
Dermatologic: Pruritus, rash.
Gastrointestinal: Constipation, diarrhea.
Genitourinary: Gynecological disorder, urinary retention.
Hepatic: Increased ALT/AST.
Local: Injection site reaction.
Neuromuscular & skeletal: Paresthesia.
Respiratory: Hypoxia.
<1%: Anaphylaxis, angina, bronchospasm, EKG changes, extrapyramidal reactions, grand mal seizures, hypokalemia, tachycardia, vascular occlusive events.
Postmarketing and/or case reports: Angioedema, cardiopulmonary arrest, dystonic reactions, flushing, hiccups, hypersensitivity reactions, hypotension, laryngeal edema, laryngospasm, oculogyric crisis, shock, shortness of breath, stridor, urticaria.
Decreased effect: Metabolized by the hepatic cytochrome P-450 enzymes; therefore, the drug's clearance and half-life may be changed with concomitant use of cytochrome P-450 inducers (eg, barbiturates, carbamazepine, rifampin, phenytoin, and phenylbutazone).
Increased toxicity: Inhibitors (eg, cimetidine, allopurinol, and disulfiram).
Store at temperature not exceeding 30°C. Protect from light.
A04AA01 - ondansetron ; Belongs to the class of serotonin (5HT3) antagonists. Used for the prevention of nausea and vomiting.
Zetron inj 4 mg/2 mL
5 × 1's
Zetron inj 8 mg/4 mL
5 × 1's
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