Understanding Anesthesiology - The Global Regional Anesthesia ...

ONDANSETRON
Class
Seratonin ( 5-HT 3 ) antagonist. Clinical use is as an antiemetic
for post-operative nausea and vomiting or for patients
receiving chemotherapy.
Mechanism of Action
Ondansetron is a highly selective competitive antagonist
of the serotonin receptor. It is believed to have its
effect centrally, possibly in the area postrema of the
brainstem where the chemoreceptive trigger zone is located.
CVS
May cause cardiac rhythm or ECG changes by prolongation
of the QT interval.
GI
Constipation, elevation of liver enzymes.
Misc.
Elimination of ondansetron is prolonged when given
with other drugs metabolized by cytochrome P450 system.
Dose
Prophylaxis (adults): 4 mg IV prior to emergence.
Prophylaxis (children): 50-150 $g/kg IV
Treatment (adults): 1-2 mg IV
Onset
Less than 30 minutes
Duration
9 hours
Elimination
Hepatic (95%)
Effects
CNS
Headache
137