Ondansetron

Ondansetron - A specific 5-HT3 antagonist.

Uses
Severe post-operative nausea and vomiting (PONV)
Highly emetogenic chemotherapy

Administration
• PONV
IV bolus: 4 mg over 3–5 min when required up to 8 hourly. Dose
may be doubled

• Highly emetogenic chemotherapy
IV bolus: 8 mg over 3–5 min, followed by two doses of 8 mg 2–4 hourly or continuous IV infusion of 1 mg/h for up to 24 hours
Dilution: 24 mg ondansetron made up to 48 ml with sodium chloride 0.9% or glucose 5% Rate of infusion: 2 ml/h

How not to use ondansetron
Do not give rapidly as IV bolus

Adverse effects
Headaches
Flushing
Constipation
Increases in liver enzymes (transient)

Cautions
Hepatic impairment

Organ failure
Hepatic: reduced clearance (moderate or severe liver disease: not > 8mg daily)