Holonyms (order Anura is a member of...): amphibia; class Amphibia (the class of vertebrates that live on land but breed in water; frogs; toads; newts; salamanders; caecilians).olonyms (order Anura is a member of...): amphibia; class Amphibia (the class of vertebrates that live on land but breed in water; frogs; toads; newts; salamanders; caecilians).
Cetirizine is not a narcotic. It's belongs to a class of drugs call 2nd generation antihistamines. It's usually used to treat Allergic Rhinitis and Hives. 2 people found this useful.
Mechanism of Action. Levocetirizine, the active enantiomer of cetirizine, is an anti histamine; its principal effects are mediated via selective inhibition of H1 receptors. The antihistaminic activity of levocetirizine has been documented in a variety of animal and human models. In vitro binding studies revealed that levocetirizine has an affinity for the human H1-receptor 2-fold higher than that of cetirizine (Ki = 3 nmol/L vs. 6 nmol/L, respectively).