Composition
Emigut 8 Tablet: Each Tablet contains Ondansetron Hydrochloride Dihydrate USP 9.975 mg equivalent to 8 mg Ondansetron.
Pharmacology
Ondansetron is a selective 5-hydroxytryptamine-3 (5-HT3) receptor antagonist with anti-emetic activity. The effect of Ondansetron in the management of the nausea and vomiting induced by cytotoxic chemotherapy and radiotherapy is probably due to antagonism of 5-HT3 receptors on neurons located both in the peripheral and central nervous system. The mechanisms of action in postoperative nausea and vomiting are not known but there may be common pathways with cytotoxic induced nausea and vomiting.
Indications
Ondansetron is used for the prevention and treatment of post-operative nausea and vomiting, and for the management of nausea and vomiting induced by cytotoxic chemotherapy and radiotherapy. Gastroenteritis in children with mild to moderate dehydration where rehydration therapy has failed.
Dosage & Administration
Postoperative Nausea and Vomiting:
The recommended dose is 16 mg (two 8 mg Tablets) 1 hour before induction of anesthesia.
Chemotherapy-induced Nausea and Vomiting:
For highly emetogenic cancer chemotherapy, the recommended adult oral dose is three 8 mg Ondansetron tablets administered 30 minutes before the start of single-day highly emetogenic chemotherapy, including cisplatin≥50 mg/m². Geriatric use is same as the general population.
For moderately emetogenic cancer chemotherapy:
Pediatric use for patients 4 to 11 years of age, the dosage is 4 mg Ondansetron given three times a day (every 8 hours). Adult oral dose is one 8 mg Ondansetron tablet given twice a day. The first dose should be administered 30 minutes before the start of emetogenic chemotherapy, with a subsequent dose 8 hours after the first dose. Ondansetron tablet should be administered twice a day (every 12 hours) for 1 to 2 days after completion of chemotherapy.
Radiotherapy-induced Nausea and Vomiting:
The recommended oral dose is one 8 mg Ondansetron tablet given three times a day.
For total body irradiation, one 8 mg Ondansetron tablet should be administered 1 to 2 hours before each fraction of radiotherapy administered each day. For single high-dose fraction radiotherapy to the abdomen, one 8 mg Ondansetron tablet should be administered 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose for 1 to 2 days after completion of radiotherapy.
For daily fractionated radiotherapy to the abdomen, one 8 mg Ondansetron tablet should be administered 1 to 2 hours before radiotherapy, with subsequent doses every 8 hours after the first dose, for each day radiotherapy is given.
Gastroenteritis in children with mild to moderate dehydration:
A reasonable weight based oral dosing regimen for infants and children is the following-
8 kg to 15 kg: 2 mg or half tsp., 15 kg to 30 kg: 4 mg or 1 tsp., greater than 30 kg: 6 mg to 8 mg or 1.5–2 tsp. Oral rehydration therapy should be initiated 15–30 minutes after administration of oral solution.
Contraindications
Ondansetron is contraindicated for patients known to have hypersensitivity to the drug.
Warning & Precautions
Hypersensitivity reactions have been reported in patients who have exhibited hypersensitivity to other selective 5-HT3 receptor antagonists. Ondansetron is not a drug that stimulates gastric or intestinal peristalsis. It should not be used instead of nasogastric suction. The use of Ondansetron in patients following abdominal surgery or in patients with chemotherapy-induced nausea and vomiting may mask a progressive ileus and/or gastric distension.
Side Effects
Common- Headache, constipation and diarrhea, but the majority has been mild or moderate in nature. In chemotherapy-induced nausea and vomiting, rash has occurred in approximately 1% of patients receiving Ondansetron. There also have been reports of a sensation of flushing and warmth, hiccups and liver enzyme abnormalities.
Rare- Anaphylaxis, bronchospasm, tachycardia, angina (chest pain), hypokalemia, shortness of breath have also been reported, except for bronchospasm and anaphylaxis, the relationship to Ondansetron is unclear. There has been no evidence to extrapyramidal reactions, in rare case oculogyric crisis appearing alone, as well as with other dystonic reactions without definite clinical evidence. In case of Post-Operative Nausea & Vomiting, with the exception of headache, rates of these events were not significantly different in the Ondansetron and placebo groups.
Use in Pregnancy and Lactation
Reproduction studies have been performed in pregnant rats and rabbits at daily oral doses up to 15 and 30 mg/kg per day, respectively, and have revealed no evidence of impaired fertility or harm to the fetus due to Ondansetron. However, no adequate and well-controlled studies in pregnant women. Ondansetron is excreted in the breast milk of rats. So caution should be exercised when Ondansetron is administered to a nursing woman.
Drug Interaction
Ondansetron does not itself appear to induce or inhibit the cytochrome P-450 drug-metabolizing enzyme system of the liver. Ondansetron is metabolized by hepatic cytochrome P-450 drug-metabolizing enzymes, so inducers or inhibitors of these enzymes may change the clearance and hence, the half-life of Ondansetron. On the basis of available data, no dosage adjustment of Ondansetron is recommended for patients on these drugs.
Carcinogenesis, Mutagenesis, Impairment of Fertility: Carcinogenic effects were not seen in 2-years studies in rats and mice with oral Ondansetron doses up to 10 and 30 mg/kg per day respectively. Ondansetron was not mutagenic in standard tests for mutagenicity. Oral administration of Ondansetron up to 15 mg/kg per day did not affect fertility or general reproduction performance of male and female rats.
Overdose
There is no specific antidote for Ondansetron overdose. In addition to the adverse effects, hypotension (and faintness) occurred in a patient who administered 48 mg of Ondansetron Hydrochloride tablets. In all instances, the events resolved completely.
Storage
Store below 30⁰C, protect from light & moisture. Keep out of the reach of children.
Packaging
Emigut 8 Tablet: Each box contains 30 tablets (10×3) in Alu-Alu blister pack.
