Antiemetics, dopamine D2-receptor antagonists

Question 1

What s it indicated?

Answer 1

Prophylaxis and treatment of nausea and vomiting in the context of reduced gut motility

Question 2

How does it work?

Answer 2

Blocks D2 receptors in chemoreceptor zone that controls nausea and vomiting pathways

Question 3

What are the side effects of this drug class?

Answer 3

Diarrhoea
Extrapydramidal effects (movement abnormalities)- EXCEPT DOMEPERDONE

Domperidone causes QT interval prolongation and arrhythmias

Prochloperazine causes drowsiness

Question 4

What are the warnings for metoclopramide?

Answer 4

Avoid neonates, children and young adults

Question 5

What are the warnings for domperidone?

Answer 5

Contraindicated in severe hepatic impairment and cardiac conduction defects and is not licenced for under 12s or weight less than 35kg

Question 6

What are the warnings for this class?

Answer 6

Avoid in Parkinson’s disease but domperidone may be used as it does not cross the BBB

Question 7

What are the interactions of this drug class?

Answer 7

Dopaminergic agents for Parkinson’s disease

Question 8

What are the interactions in regards to domperidone?

Answer 8

drugs that prolong the QT interval, such as antipsychotics, quinine, and selective serotonin reuptake inhibitors, or

▲ drugs that inhibit cytochrome P450 (CYP) enzymes (e.g. amiodarone, diltiazem, macrolides, fluconazole, protease inhibitors)