title: Safety profile of enantiomers vs. racemic mixtures: it's the same?
abstract: BACKGROUND
  The physicochemical properties of racemates and stereoisomers of medicines can differ significantly, and this may affect the side-effect profile in addition to the pharmacokinetics and intended pharmacology.
  
  
  CONCLUSIONS
  This is a study to investigate the profile of adverse drug reactions of racemic and enantiomeric forms of drugs. Our data suggest differences in the safety profile for ofloxacin and omeprazole. This area requires more work to investigate this for other compounds.
  
  
  OBJECTIVE
  The objective was to investigate the safety profile of four drugs marketed as racemic and enantiomeric forms in France.
  
  
  METHODS
  Data from the French PharmacoVigilance Data Base (January 2005 to June 2010) were analysed for four pairs of racemic/isomeric drugs. A case-noncase approach was used to measure the disproportionality of combination between adverse drug reaction (ADR) and exposure to drug.
  
  
  RESULTS
  No significant difference in the number of ADRs was observed between Rac-cetirizine/(R)-cetirizine or Rac-citalopram/(S)-citalopram pairs. (S)-Omeprazole induced more haematological effects than Rac-omeprazole. Rac-Ofloxacin induced more haematological, renal and neuropsychiatric ADRs than (S)-ofloxacin, whereas levofloxacin was associated with more reports of musculoskeletal ADRs.
  
  
  CONCLUSIONS
  The profile of ADRs could differ for some drugs marketed as racemic and enantiomeric forms. Further studies would be necessary to confirm these data.
authors.affiliation: Service de Pharmacologie Clinique, Equipe de Pharmacoépidémiologie, INSERM U 1027, Université de Toulouse, Faculté de Médecine, 37 allées Jules Guesde, Toulouse, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Caillet
authors.forename: Laurence
authors.initials: L
authors.lastname: Chauvelot-Moachon
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Montastruc
authors.forename: Haleh
authors.initials: H
authors.lastname: Bagheri
mesh_terms: D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D017332:Cetirizine / Q000009:adverse effects* / Q000737:chemistry; D015283:Citalopram / Q000009:adverse effects* / Q000737:chemistry; D016208:Databases, Factual; D005260:Female; D006801:Humans; D064704:Levofloxacin; D008297:Male; D008875:Middle Aged; D015242:Ofloxacin / Q000009:adverse effects* / Q000737:chemistry; D009853:Omeprazole / Q000009:adverse effects* / Q000737:chemistry; D013237:Stereoisomerism; D055815:Young Adult
chemical_list: D015283:Citalopram; D064704:Levofloxacin; D015242:Ofloxacin; D009853:Omeprazole; D017332:Cetirizine