title: The criteria for metformin-associated lactic acidosis: the quality of reporting in a large pharmacovigilance database.
abstract: OBJECTIVE
  To study the quality of pharmacovigilance reporting in cases of so-called 'metformin-associated lactic acidosis' and, ultimately, whether or not the criteria for this condition are indeed met.
  
  
  METHODS
  We searched for cases meeting the criteria for metformin-associated lactic acidosis [arterial pH < 7.35, blood lactate > 5 mmol/l (45 mg/dl) and detectable plasma metformin concentration] in a 15-year period (1995-2010) in a pharmacovigilance database of the license holder for metformin (Merck Serono, Lyon, France).
  
  
  RESULTS
  We found 869 reports stated as 'metformin-associated lactic acidosis' from 32 countries. The respective criteria for pH, lactate concentration and metformin concentration were met in 51.2, 53.3 and 13.9% of cases. All three criteria were met in just 10.4% of cases. By year, each of the percentages remained roughly stable throughout the study period.
  
  
  CONCLUSIONS
  The role of metformin in triggering metformin-associated lactic acidosis was assessed incorrectly in most patients and the quality of reporting did not improve over time.
authors.affiliation: Service d'Endocrinologie-Nutrition, Hôpital Sud, France.
authors.forename: F
authors.initials: F
authors.lastname: Kajbaf
authors.forename: J-D
authors.initials: JD
authors.lastname: Lalau
mesh_terms: D000140:Acidosis, Lactic / Q000139:chemically induced*; D016208:Databases, Factual / Q000592:standards; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007004:Hypoglycemic Agents / Q000009:adverse effects*; D008687:Metformin / Q000009:adverse effects*; D060735:Pharmacovigilance; D012107:Research Design / Q000592:standards
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin