Ondansetron

Question 1

class

Answer 1

antiemetic agent

Question 2

mechanism of action

Answer 2

Selectively blocks serotonin 5-HT3 receptors located in the CNS at the chemoreceptor
trigger zone and in the peripheral nervous system on nerve-terminals of the vagus nerve

Question 3

indications for use

Answer 3

nausea and vomiting

Question 4

contraindications

Answer 4

 Hypersensitivity
 Use with caution in patients with hepatic impairment
 Avoid use in patients with long QT syndrome

Question 5

adverse reactions

Answer 5

CNS: Headache, malaise, fatigue, dizziness, fever, sedation, extrapyramidal

syndrome

CV: Chest pain, arrhythmias
Resp: Hypoxia
GI/Hepatic: Diarrhea, constipation, abdominal pain, xerostomia, decreased appetite
Skin: Rash

Question 6

incompatibilities/drug interactions

Answer 6

Inducers or inhibitors of P450 drug metabolizing enzymes may alter the clearance of
Ondansetron. No dosage adjustment is recommended.

Question 7

adult dose

Answer 7

4 – 8 mg IV slow push over 2 – 5 minutes

8 mg PO ODT or tablet

Question 8

peds dose ( 1 mos to 12 years old)

Answer 8

Greater than 40 kg- 4 mg IV slow push over 2 – 5 minutes
Less than 40 kg- 0.1 mg/kg IV slow push over 2 – 5 minutes
4-12 years old 4 mg PO ODT or ODT

Question 9

route of administration

Answer 9

IV, IM, PO

Question 10

onset of action

Answer 10

unknown but probably 10-30 minutes

Question 11

peak effects

Answer 11

unknown

Question 12

duration of action

Answer 12

half-life is approximately 4 hours. Exact duration unknown but appears to be prolonged compared to half life

Question 13

AZ drug box minimum

Answer 13

optional 4 mg

Question 14

special notes

Answer 14

 Instructions for Use/Handling ZOFRAN ODT Orally Disintegrating Tablets: Do not
attempt to push ZOFRAN ODT Tablets through the foil backing. With dry hands,
PEEL BACK the foil backing of 1 blister and GENTLY remove the tablet.
IMMEDIATELY place the ZOFRAN ODT Tablet on top of the tongue where it will
dissolve in seconds, then swallow with saliva. Administration with liquid is not
necessary.
 Bottles: Store between 2°and 30°C (36 and 86°F). Protect from light. Dispense in tight,
light-resistant container as defined in the USP.
 Unit Dose Packs: Store between 2 and 30°C (36°and 86°F). Protect from light.
 Store blisters in cartons.
 ECG monitoring for patients with electrolyte abnormalities (e.g., hypokalemia or
hypomagnesemia), congestive heart failure, bradyarrhythmias, or for patients taking other
medications that can lead to QT prolongation, is recommended.