Abstract

EVALUATION OF ANTIHISTAMINE ACTIVITY

Zaseem Khan*, Imtiyaz Ansari and Dr. Vanita Kanase

Abstract

Histamine is an important chemical mediator of inflammation, vasodilation, increased vascular permeability, decreased peripheral resistance, airway smooth muscle contraction, and sensory nerve stimulation causing itching. It also plays a significant role in neurotransmission and in cardiac function. Inallergic rhinoconjunctivitis and urticaria, there strong evi-dence for the role of H1-antihistamine treatment. In asthma, additional doseresponse studies, including higher dosesof antihistamines than those used in allergic rhinitis, are neededto determine the role of antihistamines. In atopic dermatitis, the itch relieving topical glucocorticoid-sparing effects of H1-antihistamines also require further documentation. The potential benefits of each H1-antihistamine should be weighed against the potential risks, and second-generation H1-antihist-amines with excellent, well documented safety records should be used in preference to older, less safe H1-antihistamines. Second-generation H1- antihistamines are more relevant than everin the treatment of allergic disorders.[1]

Keywords: Antihistamine, histamine H1-receptor, histamine H2-receptor, histamine H3receptor, histamine H4-receptor, H1-antihis-tamine, allergic rhinitis, urticaria, asthma, atopic dermatitis, adults, children, cetirizine, desloratadine, fexofenadine, levocetirizine