title: A double-blind, single-dose, crossover comparison of cetirizine, terfenadine, loratadine, astemizole, and chlorpheniramine versus placebo: suppressive effects on histamine-induced wheals and flares during 24 hours in normal subjects.
abstract: We objectively tested the relative antihistaminic effects of cetirizine, 10 mg; terfenadine, 120 mg; terfenadine, 60 mg; loratadine, 10 mg; astemizole, 10 mg; chlorpheniramine, 4 mg; and placebo in healthy, male volunteers, mean age 25 +/- 4 years, and mean weight, 73 +/- 9 kg. The wheal areas and flare areas produced by epicutaneous tests with histamine phosphate, 1 mg/ml, before ingestion of the H1-receptor antagonist or placebo, and afterward, at 0.3 and 0.7 hours, then hourly from 1 to 12 hours and at 24 hours, were traced at 10 minutes and measured with an IBM-PC digitizer and stereometric software. In this experimental model, the H1-receptor antagonists differed significantly with regard to time of onset of action, amount of suppression of the histamine-induced wheal and flare, and duration of action. The rank order was, from most effective to least effective, cetirizine, 10 mg; terfenadine, 120 mg; terfenadine, 60 mg; loratadine, 10 mg; astemizole, 10 mg; chlorpheniramine, 4 mg; and placebo.
authors.affiliation: University of Manitoba, Health Sciences Clinical Research Center, Winnipeg, Canada.
authors.forename: F E
authors.initials: FE
authors.lastname: Simons
authors.forename: J L
authors.initials: JL
authors.lastname: McMillan
authors.forename: K J
authors.initials: KJ
authors.lastname: Simons
mesh_terms: D000328:Adult; D016589:Astemizole; D001559:Benzhydryl Compounds / Q000627:therapeutic use; D001562:Benzimidazoles / Q000627:therapeutic use; D017332:Cetirizine; D002744:Chlorpheniramine / Q000627:therapeutic use; D003533:Cyproheptadine / Q000031:analogs & derivatives / Q000627:therapeutic use; D004311:Double-Blind Method; D006632:Histamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006634:Histamine H1 Antagonists / Q000627:therapeutic use*; D006801:Humans; D006919:Hydroxyzine / Q000031:analogs & derivatives / Q000627:therapeutic use; D017336:Loratadine; D008297:Male; D010919:Placebos; D012882:Skin Tests; D016593:Terfenadine; D013997:Time Factors; D014581:Urticaria / Q000139:chemically induced / Q000188:drug therapy*
chemical_list: D001559:Benzhydryl Compounds; D001562:Benzimidazoles; D006634:Histamine H1 Antagonists; D010919:Placebos; D003533:Cyproheptadine; D006919:Hydroxyzine; D002744:Chlorpheniramine; D017336:Loratadine; D016593:Terfenadine; D016589:Astemizole; D006632:Histamine; C027556:histamine phosphate; D017332:Cetirizine