Cetirizine Uses, Side Effects, and More

 Cetirizine

Brand name:- Alerid,cetzine,zirtin,sizon 10mg tab 5mg/5ml syr. 

Cetirizine is an antihistaminic medication. It treats allergy symptoms such as itching, swelling, and rashes by blocking the effects of a chemical messenger (histamine) in the body.

Mechanism of action:-

Cetirizine is a fast-acting, highly selective antagonist of the peripheral histamine H1 receptor. The H1-receptors inhibited by cetirizine are primarily on respiratory smooth muscle cells, vascular endothelial cells, immune cells, and the gastrointestinal tract. Unlike first-generation antihistamines such as diphenhydramine and doxylamine, cetirizine does not cross the blood-brain barrier to a large extent, avoiding the neurons of the central nervous system. As a result, cetirizine produces minimal sedation compared to many first-generation antihistamines.

Given its antagonism with histamine H1-receptors, cetirizine effectively reverses many of the effects of histamine. Like other second-generation antihistamines, cetirizine decreases vascular permeability, decreasing fluid escaping to tissues from capillaries. Cetirizine is also an inhibitor of histamine-induced bronchospasm.

Cetirizine has been found to exert significant anti-inflammatory activity, reducing the infiltration of inflammatory cells in the setting of allergic rhinitis. Specifically, research has found that cetirizine minimizes the migration of neutrophils and eosinophils.

Pharmacodynamic:-

•General effects and respiratory effects

Cetirizine, the active metabolite of the piperazine H1-receptor antagonist hydroxyzine, minimizes or eliminates the symptoms of chronic idiopathic urticaria, perennial allergic rhinitis, seasonal allergic rhinitis, allergic asthma, physical urticaria, and atopic dermatitis. The clinical efficacy of cetirizine for allergic respiratory diseases has been well established in numerous trials Label.

•Effects on urticaria/anti-inflammatory effects

It has anti-inflammatory properties that may play a role in asthma management 1. There is evidence that cetirizine improves symptoms of urticaria. Marked clinical inhibition of a wheal and flare response occurs in infants, children as well as adults within 20 minutes of one oral dose and lasts for 24 h . Concomitant use of cetirizine reduces the duration and dose of topical anti-inflammatory formulas used for the treatment of atopic dermatitis .

Pharmacokinetics:-

•Absorption: Cetirizine is absorbed rapidly in the gastrointestinal tract and undergoes substantial excretion by the kidney. Cetirizine reaches peak plasma concentration after approximately one hour. Its effects typically begin after 20 to 60 minutes and persist for at least 24 hours. Food does not affect the extent of exposure (AUC) of cetirizine, but the time to attain peak concentration is delayed by 1.7 hours.

•Distribution: The mean plasma protein binding of cetirizine is 93%.

•Metabolism: Cetirizine undergoes oxidative O-dealkylation to a metabolite with negligible antihistaminic activity. Cetirizine is not a substrate of the CYP450 system. Evidence indicates that cetirizine is a P-glycoprotein substrate, which should be considered in the concurrent use of cetirizine with P-gp inhibitors.

•Excretion: The elimination half-life of cetirizine is 8.3 hours. Cetirizine is primarily excreted through the kidney.

Uses:- 

Cetirizine is used to treat cold or allergy symptoms such as sneezing, itching, watery eyes, or runny nose.

side effects:- 

Sleepiness, Fatigue, Vomiting, Dryness in mouth, Headache, Constipation.

Dose:- As Directed by your doctor.