title: Consistency and efficacy of cetirizine (10 mg) versus ebastine (20 mg) at 4 h on skin reactivity.
abstract: OBJECTIVE
  We compared the consistency and efficacy of the two antihistamines, cetirizine (10 mg) and ebastine (20 mg) on histamine skin reactivity 4 h after treatment.
  
  
  METHODS
  Twenty-four healthy volunteers participated in a randomised double-blind cross-over study. The areas of wheals and flares induced by increasing (0, 5, 10, 50, 100, 200, 300 mg/ml) histamine concentrations, administered by prick tests, were measured before and 4 h after intake of cetirizine or ebastine.
  
  
  RESULTS
  Before treatment, concentration-response curves were similar and threshold concentrations identical (0.57 mg/ml and 0.57 mg/ml for cetirizine and ebastine, respectively). Both treatments exerted a significant effect. However, cetirizine was significantly more efficient than ebastine 20 mg (P < 0.01 both for wheals and flares). After cetirizine, the threshold concentration inducing a 3-mm(2 )wheal was significantly higher (266 mg/ml) than after ebastine (77 mg/ml) (P < 0.01), and total inhibition of the wheal was obtained in 18 of 24 patients for cetirizine and in 4 of 24 for ebastine (P < 0.001). The variation coefficient for the wheal reaction was 31% for cetirizine and 159% for ebastine, indicating a much lower variability after cetirizine.
  
  
  CONCLUSIONS
  Our study shows clearly that the efficacy of a single therapeutic dosage of cetirizine is greater and consistently better than that of ebastine for suppression of cutaneous reactivity to histamine 4 h after treatment in healthy volunteers. The need for ebastine to metabolise into the active carebastine might explain this difference.
authors.affiliation: INSERM U 425, Service de Pneumologie, Hôpitaux Universitaires, Strasbourg, France.
authors.forename: A
authors.initials: A
authors.lastname: Purohit
authors.forename: C
authors.initials: C
authors.lastname: Duvernelle
authors.forename: M
authors.initials: M
authors.lastname: Melac
authors.forename: O
authors.initials: O
authors.lastname: Benabdesselam
authors.forename: G
authors.initials: G
authors.lastname: Pauli
authors.forename: N
authors.initials: N
authors.lastname: Frossard
mesh_terms: D000293:Adolescent; D000328:Adult; D018926:Anti-Allergic Agents / Q000627:therapeutic use*; D002090:Butyrophenones / Q000627:therapeutic use*; D017332:Cetirizine / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006634:Histamine H1 Antagonists / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010880:Piperidines / Q000627:therapeutic use*; D012867:Skin / Q000187:drug effects / Q000276:immunology; D012882:Skin Tests
chemical_list: D018926:Anti-Allergic Agents; D002090:Butyrophenones; D006634:Histamine H1 Antagonists; D010880:Piperidines; C058249:ebastine; D017332:Cetirizine