Ondansetron

Question 1

What is the presentation?

Answer 1

4mg wafer

4mg in 2mL vial

Question 2

What is it and what does it do?

Answer 2

Anti-nauseant and anti-emetic
Selective 5-HT3 receptor antagonist blocking serotonin centrally in the chemoreceptor trigger zone and peripherally on Vagus nerve terminals.

Question 3

What is the onset?

Answer 3

Up to 30 minutes

Question 4

What are the indications?

Answer 4

Moderate to severe nausea
Active vomiting
Prophylaxis for eye and spinal injuries

Question 5

What are the contraindications?

Answer 5

Paediatrics less than 2 years old

Hypersensitivity

Question 6

What are the precautions?

Answer 6

Oral wafer is the preferred method of administration for ALL patients unless actively vomiting.
Administer IV Ondansetron slowly over 2 minutes (neat or diluted) to prevent blurred vision and dizziness.

Question 7

What is the dose for an adult?

Answer 7

Oral wafer (preferred): 4mg wafer.
Repeat dose after 30 minutes if required.

IM or slow IV: 4mg in 2ml.
Repeat the dose after 30 minutes if required.

Question 8

What is the wafer dose for a child?

Answer 8

<15kg: 1/2 wafer

>15 kg: 1 wafer

Question 9

What is the IM dose for a child?

Answer 9

Single dose only.
2 - 5 years: 1mg in 0.5mL
6 - 9 years: 2mg in 1mL
10 - 12 years: 3mg in 1.5mL
>12 years or >40kg: 4mg in 2mL

Question 10

What are the side effects?

Answer 10

Headache
Malaise/fatigue
Drowsiness
Dizziness
Rash/allergic reaction