​Pharmacology - Cetirizine

​Pharmacology - Cetirizine 
One of the functions of cetirizine is to inhibit the actions of H1 receptors, which in turn lowers the acute hypersensivity reactions.

Mode of Action 
There is a competitive inhibitor of histamine at H1-receptors on smooth muscle.

The drug is well absorbed when taken orally, does not pass through the blood–brain barrier, is metabolized in the liver, and is eliminated through the urine.There is little to no sedation because it does not penetrate into the central nervous system.


Use in Clinical Settings
Hypersensitivity reactions include pruritus, urticaria, hay fever, and certain medication allergies. Insect bites are also on the list.

Adverse Effects 
Dry mouth, sometimes blurred vision, constipation, and urine retention are some of the effects that might occur as a result of the activity on peripheral muscarinic receptors.