Ondansetron

Question 1

Pharmacology and presentation of Ondansetron?

Answer 1

4mg in 2ml or 8mg in 4ml

An antiemetic, that antagonises 5HT3 (Serotonin) receptors in the CNS and in the PNS (GI tract) reducing Nausea and Vomiting

Question 2

Indicators of Ondansetron?

Answer 2

• Clinically significant Nausea and Vomiting

Question 3

Contraindications of Ondansetron?

Answer 3

• Known severe allergy

- Age <1 years

Question 4

Cautions of Ondansetron?

Answer 4

• None

Question 5

Side Effects of Ondansetron?

Answer 5

• Flushing

- Headache

Question 6

Dosing Regimes of Ondansetron?

Answer 6

IV Doses Adults
- 8mg:4ml, once

IV Doses Paediatrics
- <1 year contraindicated, then 2mg per 10kg, once

IM Doses Adults
- 4mg repeating same dose once after 20mins if required

IM Doses Paediatrics
- <1 year contraindicated, then 1mg per 10kg, repeating same dose once after 20mins if required

Question 7

Onset and duration of Ondansetron?

Answer 7

Onset
‐ 5 to 10 mins IM, 2 to 5 mins IV

Duration
- 4 to 8 hours