Ondansetron (Zofran, Zuplenz)
Mechanism of action
Anti-emetic medication.
Selectively antagonises the serotonin 5-HT3 receptor. This receptor, located peripherally on vagal afferents as well as centrally in the chemoreceptor trigger zone (CTZ) of the area postrema, is responsible for vomiting reflex.
Indications and dose
Pharmacokinetics
Onset of action:
- Peroral: 30 minutes; peak effect: 40 minutes
- Intravenous: rapid; peak effect: 10 minutes
Duration of action: 4 hours
Half-life of elimination: 3–4 hours
Metabolism: Hepatic
Elimination: Kidneys, Faeces
Directions for administration
In patients with moderate to severe hepatic impairment a total daily dose of 8 mg should not be exceeded.
Slow bolus should be administered over at least 30 seconds.
Medicinal forms
Tablets – 2 mg, 4 mg, 8 mg
Oral solution – 4 mg/5 ml, 8 mg/5 ml
Solution for Injection/Infusion – 2 mg/ml
- 1 vial = 4 ml (8 mg)
Side-effects
Dizziness, headache, constipation
QT interval prolongation
Bradycardia
Chest pain with or without ST segment depression
Flushing
Serotonin syndrome
References
