Ondansetron^®

Ondansetron

Generic Name: Ondansetron
Dosage Form: 2 mL solution for injection containing 2 mg of ondansetron per mL
Pharmacological Class: Antiemetic

Indications for Ondansetron:

Ondansetron is used for the prevention and treatment of nausea and vomiting.

Indications:

• Prevention and treatment of nausea and vomiting induced by chemotherapy, radiotherapy, surgery, pregnancy, or dizziness.
• Treatment of nausea in acute gastroenteritis.

Ondansetron Composition:

Each vial contains 2 mL of solution for injection, with 2 mg per mL of ondansetron.

Preparation and Administration of Ondansetron:

• Do not use if you notice any color change, turbidity, or sediment in the solution.
• Ondansetron is compatible with the following injection solutions for dilution:
• 0.9% Sodium chloride
• 5% Dextrose in 0.45% Sodium chloride
• 5% Dextrose in 0.9% Sodium chloride
• 5% Dextrose
• Ringer's solution
• Lactated Ringer's solution

Each vial is for single use only; discard any remaining content.

Method and Dosage of Ondansetron Injection:

Ondansetron can be administered through:

• Intramuscular injection
• Intravenous injection (over 2 to 5 minutes)
• Intravenous infusion (after dilution, administer over 15 minutes)

Monitoring During Ondansetron Treatment:

• ECG if applicable (eg, high-risk or older patients, concurrent use of other medications known to prolong QT interval, electrolyte abnormalities [hypokalemia or hypomagnesemia], heart failure, bradyarrhythmias, and cumulative high-dose anthracycline therapy)
• Serum potassium and magnesium levels
• Monitor for signs/symptoms of serotonin syndrome and hypersensitivity
• Monitor for decreased bowel activity (particularly in patients at risk for bowel obstruction)
• Monitor for signs/symptoms of myocardial ischemia (during and after administration).

Contraindications for Ondansetron:

• History of hypersensitivity to ondansetron, other 5-HT3 antagonists (e.g., granisetron, dolasetron), or any component of the formulation.
• Concurrent use with apomorphine.

Warnings and Precautions for Ondansetron:

• Serotonin Syndrome: If symptoms like increased body temperature, irritability, tremors, muscle rigidity, or flushing occur, contact your doctor immediately.
• Severe constipation: Consult your doctor if you experience severe constipation.
• Cardiac issues: Use with caution in patients with heart disease or arrhythmias.
• Antiemetics are most effective when used prophylactically. If emesis occurs despite optimal antiemetic prophylaxis, re-evaluate emetic risk, disease status, concurrent morbidities and current medications to assure the antiemetic regimen is optimized.

Ondansetron Use During Pregnancy and Breastfeeding:

• Pregnancy: Consult your doctor before using ondansetron during pregnancy. The decision to use this drug should be made considering the potential benefits and risks.
• Breastfeeding: Consult your doctor before using ondansetron while breastfeeding.

Side Effects of Ondansetron:

Like all medications, Ondansetron may cause side effects, though not everyone will experience them. The more common side effects include:

• Constipation
• Headache and fatigue
• Dizziness
• Hypersensitivity reactions
• Pain and burning at the injection site
• Prolonged QT interval on ECG
• Increased liver enzyme levels

Drug Interactions with Ondansetron:

Consult your doctor or pharmacist before taking ondansetron with any other drugs or supplements.

Ondansetron Packaging:

Each package contains 5 vials.

Storage Conditions for Ondansetron:

• Store the medication at below 30°C, away from light and moisture.
• Use the drug before the expiration date printed on the packaging.
• Keep out of reach of children.
• Keep the drug in its original packaging until use.

References:

1. Ondansetron: Drug Information, UpToDate, 2025
2. Medicines.org.uk – Ondansetron Product Information