title: The effectiveness of levocetirizine in comparison with loratadine in treatment of allergic rhinitis--a meta-analysis.
abstract: BACKGROUND
  Oral antihistamines are considered the gold standard therapy for allergic rhinitis to date. The goal of this investigation is to make an indirect comparison between loratadine, an oral antihistamine available over-the-counter (OTC) in the USA, and the more modern antihistamine levocetirizine. Only double-blind, placebo-controlled (DBPC) studies involving monotherapy with the active substances levocetirizine and loratadine were included in the meta-analysis.
  
  
  METHODS
  The medical databases EMBASE and Medline were searched systematically for all relevant studies completed by the end of 2009. Only DBPC studies conducted in normal environmental settings were included. Furthermore, the Jadad scale was used to guarantee the quality of the studies involved. The "standardized mean difference" (SMD) method was applied for calculating the study-specific effects to neutralize the variability between studies.
  
  
  RESULTS
  The results of a total of seven published DBPC studies met all criteria for inclusion in meta-analysis. The meta-analysis showed that levocetirizine was significantly more effective than loratadine in improving the total symptom score (TSS) (p < 0.01). The effect sizes were calculated as -0.59 (95% confidence interval -0.89, -0.29) for levocetirizine and -0.21 (95% confidence interval -0.31, -0.1) for loratadine when compared to placebo.
  
  
  CONCLUSIONS
  The results of this meta-analysis illustrate greater effectiveness for treatment with the active substance levocetirizine as monotherapy in reducing allergic symptoms when compared to treatment with loratadine.
authors.affiliation: Institute of Medical Statistics, Informatics and Epidemiology (IMSIE), University of Cologne, Cologne, Germany. ralph@moesges.de
authors.forename: Ralph
authors.initials: R
authors.lastname: Mösges
authors.forename: Volker
authors.initials: V
authors.lastname: König
authors.forename: Juliane
authors.initials: J
authors.lastname: Köberlein
mesh_terms: D018926:Anti-Allergic Agents / Q000627:therapeutic use*; D017332:Cetirizine / Q000627:therapeutic use*; D006801:Humans; D017336:Loratadine / Q000627:therapeutic use*; D012221:Rhinitis, Allergic, Perennial / Q000188:drug therapy*; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D018926:Anti-Allergic Agents; C472067:levocetirizine; D017336:Loratadine; D017332:Cetirizine