title: Cocaethylene as a biomarker to predict heavy alcohol exposure among cocaine users.
abstract: BACKGROUND
  Cocaethylene (CE) is a cocaine metabolite formed during alcohol and cocaine co-consumption. There are no previous studies to assess the effectiveness of hair CE as a biomarker indicating chronic alcohol consumption among individuals who have consumed cocaine.
  
  
  OBJECTIVE
  To establish the ability of CE to predict chronic alcohol use among individuals testing positive for cocaine.
  
  
  METHODS
  We studied all cases referred to our laboratory where both chronic cocaine and alcohol consumption were sought, and values of hair cocaine, benzoylegconine (BE), CE, and FAEEs (as marker of chronic alcohol consumption ) were available. Cocaine, BE and CE were screened by ELISA and confirmed using headspace-solid phase microextraction (HS-SPME) and GC-MS. FAEE were analyzed using HS-SPME and GC-MS/EI. Sensitivity, specificity, and predictive values of CE as a marker of alcohol consumption among cocaine users were calculated using different FAEE cutoffs.
  
  
  RESULTS
  Cocaine (P<0.001) and BE (P<0.001) concentrations were associated with increased FAEE. The positive predictive value of CE to identify alcohol consumption was 0.66 for excessive drinking and 0.76 for chronic drinking among positive cocaine users. Negative CE ruled out almost completely excessive alcohol consumption.
  
  
  CONCLUSIONS
  Positive hair CE results had high specificity for chronic excessive alcohol consumption among cocaine users. With no established safe level of alcohol in pregnancy, identification of CE in hair of pregnant women who have used cocaine can serve as a biomarker for fetal alcohol spectrum disorder.
authors.affiliation: Division of Clinical Pharmacology and Toxicology, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Aniket
authors.initials: A
authors.lastname: Natekar
authors.forename: Ilan
authors.initials: I
authors.lastname: Motok
authors.forename: Paula
authors.initials: P
authors.lastname: Walasek
authors.forename: Chitra
authors.initials: C
authors.lastname: Rao
authors.forename: Georgina
authors.initials: G
authors.lastname: Clare-Fasullo
authors.forename: Gideon
authors.initials: G
authors.lastname: Koren
mesh_terms: D000428:Alcohol Drinking / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis; D003042:Cocaine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D000431:Ethanol / Q000008:administration & dosage / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D063647:Fetal Alcohol Spectrum Disorders / Q000175:diagnosis; D008401:Gas Chromatography-Mass Spectrometry; D006197:Hair / Q000737:chemistry; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D012680:Sensitivity and Specificity; D052617:Solid Phase Microextraction; D015813:Substance Abuse Detection / Q000379:methods
chemical_list: D015415:Biomarkers; D005227:Fatty Acids; D000431:Ethanol; C005618:benzoylecgonine; C066444:cocaethylene; D003042:Cocaine