Ondansetron

Question 1

**Ondansetron **
Drug Class

Answer 1

Anti emetic – Serotonin 5-HT3 receptor antagonist. Blocks the action of serotonin which may cause nausea and vomiting

Question 2

Ondansetron
Onset

Answer 2

5 mins

Question 3

Ondansetron
Duration

Answer 3

Several hours

Question 4

**Ondansetron **
Indications

Answer 4

• Moderate to severe nausea
• Active vomiting
• Nausea and vomiting prophylaxis for eye and spinal injuries

Question 5

Ondansetron
Contraindications

Answer 5

• Hypersensitivity to ondansetron
• Treatment with apomorphine (risk of svere hypotension and loss of consciousness)
• Paediatrics less than 2 years old

Question 6

Ondansetron
Oral
Dose

Answer 6

Adult:

• 4 mg oral wafer.
• may be repeated after 15 minutes.
• Total max dose 8mg in 8-hour period.

**
Paediatric (>4 years or >15kg):**

• 4 mg oral wafer, no repeat

Question 7

Ondansetron
Intra Muscular (IM)
Dose

Answer 7

Adult:

• 4 mg IM injection
• may be repeated after 15 minutes.
• Total max dose 8mg in 8-hour period.

Paediatric (>2 years):

0.1 mg/kg up to 4 mg, single dose only in 8-hour period.

Question 8

Ondansetron
IV / IO
Dose

Answer 8

Adult:

• 4 mg over at least 30 secs but preferably 3-5 mins
• may be repeated after 15 minutes
• Total max dose 8mg in 8-hour period.

Note: Over 75 years: inject slowly as more susceptible to side effects

Paediatric: (>2 years):

0.1 mg/kg up to 4mg over 3-5 mins, single dose only in 8-hour period.

Question 9

** Ondansetron**
Side Effects

Answer 9

Common >1%
* Headache
* Constipation
Rare <.01%
* Hypersensitivity reactions (including anaphylaxis)
* ECG changes