Trade Names:Ondansetron Hydrochloride- Tablets 16 mg (as hydrochloride dihydrate)- Injection 32 mg/50 mL (as hydrochloride dihydrate)
Trade Names:Zofran- Tablets 4 mg (as hydrochloride dihydrate)- Tablets 8 mg (as hydrochloride dihydrate)- Tablets 24 mg (as hydrochloride dihydrate)- Solution, oral 4 mg/5 mL (5 mg as hydrochloride dihydrate)- Injection 2 mg/mL (as hydrochloride dihydrate)
Trade Names:Zofran ODT- Tablets, orally-disintegrating 4 mg (as base)- Tablets, orally-disintegrating 8 mg (as base)Apo-Ondansetron (Canada)PMS-Ondansetron (Canada)ratio-Ondansetron (Canada)Sandoz Ondansetron (Canada)
Selective serotonin (5-HT 3 ) receptor antagonist that inhibits serotonin receptors in GI tract or chemoreceptor trigger zone.
Passively and completely absorbed from GI tract. Bioavailability is 48% to 75% and is slightly enhanced with food.
C max for males is 24.1 to 37 ng/mL (8 mg oral dose). C max for females is 42.7 to 52.4 ng/mL (8 mg oral dose). C max for injection is 102 to 170 ng/mL. T max for males is 2 to 4.1 h (8 mg dose). T max for females is 1.7 to 4.9 h (8 mg dose).
Plasma protein binding is 70% to 76%.
Extensively metabolized in the liver by hydroxylation, followed by glucuronide or sulfate conjugation; CYP1A2, CYP2D6, CYP3A4 are the main hepatic enzymes.
Approximately 5% is eliminated as parent compound in urine. The t ½ for males is 2.1 to 4.5 h (8 mg oral dose). The t ½ for females is 1.9 to 6.2 h (8 mg dose). The t ½ for injection is 3.5 to 5.5 h. Plasma Cl is 0.262 to 0.381 L/h/kg.
In elderly older than 75 yr of age, there is a reduction in Cl and an increase in elimination half-life. No dosage adjustment is necessary.Gender
The extent and rate of absorption is greater in women than in men. There is slower Cl, a smaller volume of distribution, and higher bioavailability in women.Severe Hepatic Function Impairment
Cl is reduced 2- to 3-fold. The volume of distribution is increased. The half-life is increased to 20 h. Bioavailability approaches 100%. A total daily dose of 8 mg should not be exceeded.Severe Renal Function Impairment
There is a reduction in Cl. Oral plasma Cl was reduced by 50%. No dosage adjustment is necessary.
Prevention of nausea and vomiting with initial and repeat courses of emetogenic cancer chemotherapy, including high-dose cisplatin; prevention of postoperative nausea or vomiting.Oral
Prevention of nausea and vomiting associated with radiotherapy in patients receiving either total body irradiation, single high-dose fraction to the abdomen, or daily fractions to the abdomen; prevention of nausea and vomiting associated with highly emetogenic cancer chemotherapy, including cisplatin 50 mg/m 2 or more.
Treatment of nausea and vomiting associated with acetaminophen poisoning or prostacyclin therapy; treatment of acute levodopa-induced psychosis (visual hallucinations); reduction in bulimic episodes due to bulimia nervosa; treatment of spinal or epidural morphine-induced pruritus; management of social anxiety disorder.
IV 0.15 mg/kg infused over 15 min beginning 30 min before emetogenic chemotherapy with 2 additional 0.15 mg/kg doses 4 and 8 h after the first dose. Alternatively, infuse 32 mg over 15 min, starting 30 min prior to emetogenic chemotherapy.Adults and children 12 yr of age and older
PO (moderately emetogenic cancer chemotherapy) 8 mg twice daily, administering the first dose 30 min prior to starting emetogenic chemotherapy and the second dose 8 h after the first dose; subsequent 8 mg doses may be given every 12 h for 1 to 2 days after completion of chemotherapy.Children 4 to 11 yr of age
PO 4 mg 3 times daily, starting 30 min prior to chemotherapy, with subsequent doses 4 and 8 h after the first dose; give 4 mg every 8 h for 1 to 2 days after completion of chemotherapy.Prevention of Radiotherapy-Induced Nausea and VomitingAdults
PO 8 mg 3 times daily.Total Body IrradiationAdults
PO 8 mg 1 to 2 h prior to each fraction of radiotherapy administered each day.Single High-Dose Fraction Radiotherapy to the AbdomenAdults
PO 8 mg 1 to 2 h prior to radiotherapy, with subsequent doses every 8 h after the first dose for 1 to 2 days after completion of radiotherapy.Daily Fractionated Radiotherapy to the AbdomenAdults
PO 8 mg 1 to 2 h prior to radiotherapy, with subsequent doses every 8 h after the first dose for each day radiotherapy is given.Prevention of Postoperative Nausea and VomitingAdults
IV 4 mg (undiluted) over 30 sec (preferably over 2 to 5 min) or IM 4 mg (undiluted) as a single injection. PO 16 mg as a single dose 1 h prior to induction of anesthesia.Children (2 to 12 yr of age weighing 40 kg or less)
IV 0.1 mg/kgChildren (more than 40 kg)
IV 4 mg single dose. Administer over 30 sec or longer, preferably over 2 to 5 min.Prevention of Nausea and Vomiting due to Highly Emetogenic Cancer ChemotherapyAdults
PO 24 mg given 30 min prior to start of single-day highly emetogenic chemotherapy, including 50 mg/m 2 or more cisplatin.
Plasma levels of ondansetron may be reduced, decreasing the antiemetic effect.
None well documented.
Chest pain; tachycardia.
Dry mouth; constipation; abdominal pain.
Fever; anaphylaxis; weakness.
Category B .
Dosing in children younger than 4 yr of age is not well defined.
In patients with severe hepatic function impairment, do not exceed 8 mg/day oral dose. For IV use, give single 8 mg/day dose over 15 min beginning 30 min before chemotherapy.
Ondansetron does not stimulate gastric or intestinal peristalsis; may mask progressive ileus or gastric distention.
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