Cinnarizine

Question 1

What is Cinnarizine

Answer 1

an antihistamine and a calcium channel blocker

Question 2

which receptors does Cinnarizine block

Answer 2

inhibits dopamine D2 receptors, histamine H1 receptors, muscarinic acetylcholine receptors, and also vascular smooth muscle contraction

Question 3

how does Cinnarizine inhibit vascular smooth muscle contraction

Answer 3

blockage of L-type and T-type voltage gated calcium channels.

Question 4

Class

Answer 4

Histamine H1 receptor antagonist

Question 5

Action

Answer 5

Antiemetic

Sedative

Question 6

Mechanisms of Actions

Answer 6

Reversible competitive
antagonist at H1 receptors
Antiemetic action is due to
blocking H1 receptors in
the vestibular nuclei and in
the vomiting centre

Question 7

Clinical Uses

Answer 7

Motion sickness and
other emesis of
vestibular origin
Vomiting in early
pregnancy
Emesis due to local
stimuli in the gut acting
via the vagus

Question 8

Adverse Effects

Answer 8

Sedative action may
not be desirable
Causes confusion in
elderly
Dry mouth
(anticholinergic
action)
Potentially fatal
respiratory depression
in infants under 2
years old