title: Different black box warning labeling for same-class drugs.
abstract: BACKGROUND
  Black box warnings (BBWs) are the strongest medication-related safety warnings in a drug's labeling information and highlight major risks. Absence of a BBW or asynchronous addition of a BBW among same-class drugs could have major implications.
  
  
  METHODS
  We identified the 20 top-selling drugs in 2008 (10 with BBWs and 10 without BBWs on their label) that belonged to different drug classes. We collected labeling information on all drugs belonging in these 20 classes, and recorded differences in the presence and timing of acquisition of BBWs for same-class drugs.
  
  
  RESULTS
  Across the 20 evaluated drug classes, we identified 176 different agents, of which 7 had been withdrawn for safety reasons. The reasons for the withdrawals became BBWs in other same-class agents only in two of the seven cases. Differences were identified in 9 of the 20 classes corresponding to 15 BBWs that were not present in all drugs of the same class. The information for 10 of the 15 different BBWs were included in the labels of same-class drugs as simple warnings or text, while it was absent entirely in 5 BBWs. The median interval from the time the BBW had appeared in another drug of the same class was 66 months.
  
  
  CONCLUSIONS
  Differences in BBW labeling in same-class drugs are common and shape impressions about the safety of similar agents. BBW labeling needs to become more systematic.
authors.affiliation: Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece.
authors.forename: Orestis A
authors.initials: OA
authors.lastname: Panagiotou
authors.forename: Despina G
authors.initials: DG
authors.lastname: Contopoulos-Ioannidis
authors.forename: Panagiotis N
authors.initials: PN
authors.lastname: Papanikolaou
authors.forename: Evangelia E
authors.initials: EE
authors.lastname: Ntzani
authors.forename: John P A
authors.initials: JP
authors.lastname: Ioannidis
mesh_terms: D016208:Databases, Factual; D004348:Drug Labeling / Q000379:methods / Q000592:standards*; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D004364:Pharmaceutical Preparations / Q000145:classification*; D056737:Safety-Based Drug Withdrawals / Q000379:methods; D014481:United States; D014486:United States Food and Drug Administration / Q000592:standards
chemical_list: D004364:Pharmaceutical Preparations