Antiemetics histamine

Question 1

Antiemetics histamine main indications

Answer 1

Nausea and vomiting especially in motion sickness and vertigo

Question 2

Antiemetics histamine moa

Answer 2

Pathways converge in vomiting centre in medulla receiving inputs from elsewhere e.g. CTZ, it has histamine and acetylcholine receptors in it (vomiting centre and receptors in vestibular system). Blocking the receptors makes them useful especially for motion or vertigo

Question 3

Antiemetics histamine side effect

Answer 3

Drowsy (especially cyclizine), anticholinergic/antimuscainics effects like dry mouth, if IV then transient tachycardia

Question 4

Who should histamine antiemetics be avoided in

Answer 4

hepatic encephalopathy due to sedation and those already susceptible to anticholinergic side effects like prostatic hypertrophy

Question 5

Antiemetic histamine interactions

Answer 5

Pharmacodynamic, other sedative drugs like benzos and other anticholinergics like tiotropium

Question 6

Antiemetic histamine examples

Answer 6

Cyclizine, cinnarizine, promethazine

Question 7

Best admin for antiemetic histamine if oral route inappropriate due to vomiting

Answer 7

slow IV injection, over about 2 minutes

Question 8

What antimuscarinic can be used to treat motion sickness otc

Answer 8

Hyoscine hydrobromide