title: Suppression of histamine-induced pruritus by three antihistaminic drugs.
abstract: A double-blind crossover study of inhibition of histamine-induced pruritus by three commonly prescribed antihistamines was conducted on 28 normal subjects. Drugs used included diphenhydramine HCl (Benadryl), cyproheptadine (Periactin), hydroxyzine HCl (Atarax), and a lactose placebo in identical capsules. Intradermal histamine dose-response thresholds of pruritus were obtained before and after pretreatment with the three antihistamines and placebo in each subject. Analysis of data revealed a fivefold increase above baseline of the histamine dose required to produce pruritus following both cyproheptadine and placebo. This compared to a tenfold increase following diphenhydramine and a 750-fold increase following hydroxyzine HCl. The most common side effect was drowsiness, which occurred with all three drugs.
mesh_terms: D000293:Adolescent; D000328:Adult; D002986:Clinical Trials as Topic; D003533:Cyproheptadine / Q000009:adverse effects / Q000627:therapeutic use; D004056:Differential Threshold; D004155:Diphenhydramine / Q000009:adverse effects / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D006632:Histamine / Q000008:administration & dosage; D006634:Histamine H1 Antagonists / Q000627:therapeutic use*; D006801:Humans; D006919:Hydroxyzine / Q000009:adverse effects / Q000627:therapeutic use; D007785:Lactose / Q000627:therapeutic use; D010919:Placebos; D011537:Pruritus / Q000139:chemically induced* / Q000188:drug therapy
chemical_list: D006634:Histamine H1 Antagonists; D010919:Placebos; D003533:Cyproheptadine; D006919:Hydroxyzine; D006632:Histamine; D004155:Diphenhydramine; D007785:Lactose