5-HT3 receptor antagonists

Question 1

MoA

Answer 1

Block 5-HT3 receptors in the chemoreceptor trigger zone and GIT
5-HT is a key neurotransmitter released by gut in response to emetogenic stimuli

Question 2

Examples

Answer 2

Granisetron
Ondansetron
Palonosetron

Question 3

Palonosetron

Answer 3

Prevention of N + V associated with moderately/highly emetogenic cytotoxic chemo

Question 4

Indications - Granisetron/Ondansetron

Answer 4

PONV
Chemo induced N + V

Question 5

Side effects

Answer 5

QT interval prolongations

Question 6

Increased risk of QT prolongation

Answer 6

Amiodarone
Clarithromycin
Quinine
Sumatriptan
Lithium
Antipsychotics

Question 7

Increased risk of torsades de pointes

Answer 7

Increased risk of hypokalaemia = torsades de pointes
- Loop/thiazide diuretics
- Corticosteroids
- Beta agonists (salbutamol, theophylline)
- Stimulant laxative abuse
- Amphoteracin B

Question 8

Increased risk of serotonin syndrome

Answer 8

5-HT1a agonists
- Sumatriptan
- MAOIs
- SSRIs