Zofran Injection (Ondansetron Hydrochloride Dihydrate)

Adult dosage

1. Nausea and vomiting induced by cytotoxic chemotherapy or radiotherapy 1) Adults The emetogenic potential of cancer treatment varies according to the dose of chemotherapy, concomitant medications, and type of radiotherapy. The route and dosage may be selected as appropriate within a range of ondansetron 8∼32mg per day, administered orally, intravenously, or intramuscularly. (1) For chemotherapy and radiotherapy with relatively low emetogenic potential ① Immediately before chemotherapy or radiotherapy, administer ondansetron 8mg by slow intravenous injection (over at least 30 seconds) or intramuscular injection. ② To prevent delayed vomiting, administer 8mg orally per dose, twice daily, for up to 5 days after treatment. (2) For highly emetogenic chemotherapy (e.g., high-dose cisplatin) ① Immediately before chemotherapy, administer ondansetron 8mg by slow intravenous injection (over at least 30 seconds) or intramuscular injection, and administer two additional 8mg doses by intravenous injection (over at least 30 seconds) or intramuscular injection at 4-hour intervals; alternatively, administer by intravenous infusion at a rate of 1mg per hour for up to 24 hours. ② Alternatively, dilute ondansetron 16mg in 50∼100mL of normal saline or another compatible injection solution and infuse intravenously over at least 15 minutes immediately before chemotherapy. ③ Do not exceed a single dose of 16mg, as the risk of QT prolongation increases in a dose-dependent manner. ④ The effect of this drug may be enhanced by slowly administering dexamethasone sodium phosphate 20mg intravenously before chemotherapy. ⑤ To prevent delayed vomiting, administer 8mg orally per dose, twice daily, for up to 5 days after treatment. 3) Older adults For patients aged 65 to 74 years, follow the adult recommended dose. For intravenous administration, dilute each dose in 50∼100mL of normal saline or another compatible injection solution and infuse over at least 15 minutes. For patients aged 75 years and older, the initial intravenous dose should not exceed 8mg. For intravenous administration, dilute each dose in 50∼100mL of normal saline or another compatible injection solution and infuse over at least 15 minutes. 4) Patients with renal impairment No special dosage adjustment is required. 5) Patients with hepatic impairment In patients with moderate to severe hepatic impairment, clearance of this drug is significantly reduced and serum half-life is markedly prolonged; therefore, do not exceed 8mg per day. 2. Postoperative nausea and vomiting 1) Adults (1) Prevention of postoperative nausea and vomiting Administer 4mg once by slow intravenous or intramuscular injection at induction of anesthesia. (2) Treatment of postoperative nausea and vomiting Administer 4mg once by slow intravenous or intramuscular injection. 3) Older adults Experience with use in patients aged 65 years and older is limited, but tolerability was good in patients who received chemotherapy. 4) Patients with renal impairment No special dosage adjustment is required. 5) Patients with hepatic impairment In patients with moderate to severe hepatic impairment, clearance of this drug is significantly reduced and serum half-life is markedly prolonged; therefore, do not exceed 8mg per day. 6) Patients with impaired sparteine/debrisoquine metabolism The elimination half-life of this drug is unchanged in patients with impaired sparteine/debrisoquine metabolism. Repeated administration in these patients does not result in exposure different from that in the general population; therefore, adjustment of the daily dose, dosing frequency, or route of administration is not required.

Children's dosage

1. Nausea and vomiting induced by cytotoxic chemotherapy or radiotherapy 2) Pediatric patients (6 months and older) The dose may be calculated based on body surface area or body weight. The total daily dose based on body weight is higher than that based on body surface area. Zofran injection should be diluted with 5% dextrose injection, 0.9% sodium chloride injection, or another compatible injection solution and infused intravenously over at least 15 minutes. In pediatric clinical trials, ondansetron was diluted in 25~50mL of normal saline or another compatible injection solution and infused intravenously over at least 15 minutes. (1) Immediately before chemotherapy, administer ondansetron 5mg/㎡ (body surface area) intravenously. Administer the oral dose 12 hours after the intravenous dose and continue for up to 5 days. (Table 1) Table 1. Dosage based on body surface area (6 months and older) < 0.6 ㎡ — Day 1: 5mg/㎡ intravenously, then 2mg orally 12 hours later; days 2~6: 2mg per dose orally every 12 hours; a: Do not exceed a maximum intravenous dose of 8mg. b: The total daily dose should not exceed the adult dose of 32mg. ≥ 0.6 ㎡, 1.2㎡ ≤ — Day 1: 5mg/㎡ intravenously, then 4mg orally 12 hours later; days 2~6: 4mg per dose orally every 12 hours; a: Do not exceed a maximum intravenous dose of 8mg. b: The total daily dose should not exceed the adult dose of 32mg. > 1.2㎡ — Day 1: 5mg/㎡ or 8mg intravenously, then 8mg orally 12 hours later; days 2~6: 8mg per dose orally every 12 hours; a: Do not exceed a maximum intravenous dose of 8mg. b: The total daily dose should not exceed the adult dose of 32mg. (2) Alternatively, immediately before chemotherapy, administer ondansetron 0.15 mg/kg intravenously. Two additional intravenous doses may be administered at 4-hour intervals. Administer the oral dose 12 hours after the intravenous dose and continue for up to 5 days. (Table 2) Table 2. Dosage based on body weight (6 months and older) ≤ 10 kg — Day 1: 0.15 mg/kg per dose intravenously every 4 hours for up to 3 doses; days 2~6: 2mg per dose orally every 12 hours; a: Do not exceed a maximum intravenous dose of 8mg. b: The total daily dose should not exceed the adult dose of 32mg. > 10 kg — Day 1: 0.15 mg/kg per dose intravenously every 4 hours for up to 3 doses; days 2~6: 4mg per dose orally every 12 hours; a: Do not exceed a maximum intravenous dose of 8mg. b: The total daily dose should not exceed the adult dose of 32mg. (3) Do not exceed a maximum intravenous dose of 8mg. The total daily dose should not exceed the adult dose of 32mg. (4) There are no controlled clinical trial data on prevention of delayed or persistent nausea and vomiting induced by emetogenic chemotherapy. There are no controlled pediatric clinical trial data on nausea and vomiting induced by radiotherapy. 2. Postoperative nausea and vomiting 2) Pediatric patients (2 years and older) (1) Prevention of postoperative nausea and vomiting Before, during, or after induction of anesthesia, administer 0.1mg/kg up to a maximum of 4mg once by slow intravenous injection. (2) Treatment of postoperative nausea and vomiting Administer 0.1mg/kg up to a maximum of 4mg once by slow intravenous injection. (3) There are insufficient data in children under 2 years of age for prevention and treatment of postoperative nausea and vomiting. (4) No clinical trials have been conducted on the use of oral ondansetron for prevention and treatment of postoperative nausea and vomiting; slow intravenous injection (over at least 30 seconds) is recommended.

This medication is provided as an injection and requires careful cutting of the glass ampule when used. Caution is especially needed when administering to children or the elderly, as glass fragments could cause side effects. Persons with allergic reactions to any components of this medication should not use it. Additionally, administering it along with a specific medication, apomorphine hydrochloride, can result in severe hypotension and loss of consciousness, so these two medications should not be used together. Patients who have previously experienced allergic reactions to similar medications should be cautious when using this drug, and if respiratory issues or hypersensitivity symptoms occur, immediate treatment is necessary. This medication can slow bowel motility, so it should be administered cautiously to patients with bowel obstruction symptoms. Patients with severe liver dysfunction also need to be cautious when using this medication. This medication may prolong the QT interval of heart electrical signals, so patients with heart disease or electrolyte imbalances should have their conditions well assessed and be observed carefully before administration. Furthermore, co-administration of this drug with other serotonin-acting medications can lead to severe side effects known as serotonin syndrome, requiring close monitoring of the patient's condition during concomitant use. When used for the prevention of nausea and vomiting after surgery, care should be taken as bleeding may be concealed, and careful observation is necessary after administration. Pediatric patients using this medication may experience side effects similar to those in adults, so caution is advised. Possible side effects include allergic reactions, headaches, dizziness, diarrhea or constipation, palpitations, hypotension, liver function abnormalities, transient vision disturbances, rashes on the skin, etc. Using this drug during pregnancy, especially in the first trimester, may pose risks to the fetus, so its use should be avoided if possible, and women of childbearing potential must confirm pregnancy status before use. Breastfeeding women are advised to discontinue breastfeeding as this drug can be passed into breast milk. In case of overdose, visual disturbances, severe constipation, hypotension, etc., may appear, and medical assistance should be sought immediately. Care should be taken when mixing this medication with other drugs, and only the recommended injection solutions should be used for mixing. During storage, it should be kept in a sealed container away from direct sunlight and out of reach of children, and transferring to other containers should be avoided.

Rash, itching, anaphylaxis, headache, heaviness in the head, drowsiness, reddening of the face, warmth in the head and abdomen, transient asymptomatic increase in aminotransferases, dizziness, ocular movement seizures, muscle tone abnormalities, movement disorders, seizures, diarrhea, constipation, palpitations, increased blood pressure, chest pain, arrhythmia, hypotension, bradycardia, QTc prolongation, transient asymptomatic elevation in liver function test items, transient visual disturbances, transient vision loss, toxic skin rash, toxic epidermal necrolysis, involuntary movements, heat sensation, generalized fatigue, hiccups, sweating, vascular pain, localized hypersensitivity reaction at injection site, myocardial ischemia, visual impairment, severe constipation, transient second-degree atrioventricular block, signs of vagal nerve dysfunction.

This medication should be stored in a sealed container to prevent exposure to air or light, ideally in a cool place below 30 degrees Celsius. Proper storage will help maintain the medication’s effectiveness over a longer period.

Appearance

A colorless, transparent liquid in a colorless, transparent glass ampule for injection.

Package unit

10 ampules/box [(2 milliliters/ampule) x 10], 8 ampules/box [(4 milliliters/ampule) x 8]