What is the protocol for an Ondansetron (Zofran) drip?

From the Guidelines

Ondansetron should be administered as an 8 mg or 0.15 mg/kg IV dose for managing severe nausea and vomiting, particularly in hospitalized patients, as recommended by the most recent guidelines 1. The standard dosing for ondansetron can vary depending on the emetic risk category of the patient, but for high-risk categories such as those receiving cisplatin or anthracycline combined with cyclophosphamide, a single 24-mg dose administered by tablets, successive oral dissolving tablets, or oral dissolving film applications before the start of chemotherapy, or 8 mg or 0.15 mg/kg IV is recommended 1. Some key points to consider when administering ondansetron include:

• The maximum daily dose should not exceed 32 mg due to the risk of QT prolongation.
• Monitor patients for side effects including headache, dizziness, constipation, and ECG changes.
• Ondansetron works by blocking serotonin (5-HT3) receptors in the chemoreceptor trigger zone and gastrointestinal tract, preventing the stimulation of the vomiting center in the brain and reducing nausea signals. It's also important to note that ondansetron can be used in combination with other antiemetic agents, such as NK1-receptor antagonists and dexamethasone, to provide optimal antiemetic control 1. In terms of administration, ondansetron can be given orally or intravenously, and the choice of route depends on the patient's ability to tolerate oral medications and the severity of their nausea and vomiting. For patients who require continuous infusion, a dose of 1 mg/hour can be prepared by adding 24 mg of ondansetron to 250 mL of compatible fluid (normal saline or D5W) and infusing at 10.4 mL/hour, but this is not the recommended dosing according to the most recent guidelines 1.

From the FDA Drug Label

2 DOSAGE & ADMINISTRATION

2.1 Prevention of Nausea and Vomiting Associated with Initial and Repeat Courses of Emetogenic Chemotherapy Important Preparation Instructions • Dilution of Ondansetron Injection in 50 mL of 5% Dextrose Injection or 0. 9% Sodium Chloride Injection is required before administration to adult and pediatric patients for the prevention of nausea and vomiting associated with emetogenic chemotherapy.

Dosage and Administration The recommended dosage for adult and pediatric patients 6 months of age and older for prevention of nausea and vomiting associated with emetogenic chemotherapy is 0. 15-mg/kg per dose for 3 doses (maximum of 16 mg per dose). Caution: Dilution of Ondansetron Injection is required in adult and pediatric patients prior to administration. Infuse intravenously over 15 minutes beginning 30 minutes before the start of emetogenic chemotherapy and then repeat 4 and 8 hours after the first dose.

The ondansetron drip should be administered as follows:

• Dilution: Dilute ondansetron in 50 mL of 5% Dextrose Injection or 0.9% Sodium Chloride Injection.
• Dosage: 0.15-mg/kg per dose for 3 doses (maximum of 16 mg per dose).
• Administration: Infuse intravenously over 15 minutes, beginning 30 minutes before the start of emetogenic chemotherapy, and then repeat 4 and 8 hours after the first dose 2.

From the Research

Ondansetron Drip

• Ondansetron is a serotonin antagonist used to treat nausea and vomiting 3, 4, 5, 6
• It is commonly used in the emergency department setting, but there is no consensus on the optimum drug treatment for nausea and vomiting in adults 3
• A study found that ondansetron was not statistically significantly superior to placebo in reducing nausea and vomiting, but it may be effective in specific cases 3
• Ondansetron is often used in combination with other medications, such as dexamethasone, to prevent delayed nausea and vomiting induced by chemotherapy 5 or to reduce severe nausea and vomiting in patients receiving fentanyl-based intravenous patient-controlled analgesia 6

Efficacy and Safety

• The efficacy of ondansetron in treating nausea and vomiting is variable, and it may not be effective in all cases 3, 4, 7
• Ondansetron is generally well-tolerated, but it can cause adverse events such as headache, dizziness, and constipation 3, 4, 6
• The safety of ondansetron has been evaluated in several studies, and it is considered to be a safe medication when used as directed 3, 4, 5, 6

Clinical Use

• Ondansetron is often used to treat nausea and vomiting caused by chemotherapy, radiation therapy, and surgery 4, 5, 6
• It is also used to treat nausea and vomiting caused by other conditions, such as gastroenteritis and vestibular disturbances 7
• The choice of ondansetron as a treatment for nausea and vomiting depends on the underlying cause of the symptoms and the patient's individual needs 3, 4, 7