DRUG OF THE DAY
ondansetron
Serotonin 5-HT3 receptor antagonist antiemetic
Before opening the card, recall one use, one safety check and one counseling point.
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Names and formulations
- Ondansetron hydrochloride: film-coated oral tablet
The bound label covers film-coated oral tablets. Other oral dosage forms and injections have separate handling and administration instructions.
Common use
Prevention of nausea and vomiting associated with emetogenic chemotherapy, radiotherapy, or surgery, depending on formulation and regimen.
Mechanism of action
Blocks 5-HT3 receptors centrally and on vagal afferents involved in the vomiting reflex.
Important adverse effects and monitoring
- Can prolong QT and has been associated with torsades de pointes; correct electrolyte abnormalities and use ECG monitoring in higher-risk patients.
- Serotonin syndrome has been reported, especially with other serotonergic medicines.
- May mask progressive ileus or gastric distention after abdominal surgery or chemotherapy.
Patient counseling
- Take the film-coated tablet exactly as prescribed; do not substitute another dosage form without checking its instructions.
- Report fainting, palpitations, severe agitation, muscle rigidity, or persistent abdominal distention.
Interaction to recognize
With: apomorphine
Why it matters: The combination has caused profound hypotension and loss of consciousness.
Practical response: Concomitant use is contraindicated.
Check the original sources
- DailyMed — ondansetron prescribing information
Sections: 1 Indications and Usage; 4 Contraindications; 5 Warnings and Precautions; 7 Drug Interactions; 12.1 Mechanism of Action; 17 Patient Counseling Information. Source checked 2026-09-13.
Selected learning points; verify current labeling for the complete prescribing information.