title: Laboratory diagnosis of toluene-based inhalants abuse.
abstract: Toluene is the main substance contained in products used as inhalants. The frequent abuse of toluene-based inhalants requires the definition of a simple laboratory parameter that allows acute exposure assessment. This study aimed at defining urinary hippuric acid (UHA) levels related to intentional exposure to toluene, and to correlate them to blood toluene concentration (BT).
  
  
  METHODS
  BT and UHA levels were measured in 65 homeless adolescents of Porto Alegre, Brazil.
  
  
  RESULTS
  Toluene was detected in 91.9% of the investigated population, who presented BT levels from 0.5 to 83.7 microg/mL. There was good correlation between UHA and BT concentrations (r = 0.78), and in homeless adolescents, UHA levels higher than 3.0 g/g creatinine indicate intentional exposure to toluene.
  
  
  CONCLUSIONS
  The determination of UHA concentrations can be used as a screening method for the detection of intentional exposure to toluene, but its diagnosis must include BT toluene dosage, as well as circumstantial and clinical evidence.
authors.affiliation: Pharmacy Faculty and Toxicology Institute, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil. fvthiesen@pucrs.br
authors.forename: Flavia Valladão
authors.initials: FV
authors.lastname: Thiesen
authors.forename: Ana Regina
authors.initials: AR
authors.lastname: Noto
authors.forename: Helena M T
authors.initials: HM
authors.lastname: Barros
mesh_terms: D000293:Adolescent; D001938:Brazil; D019411:Clinical Laboratory Techniques; D006626:Hippurates / Q000652:urine*; D018453:Homeless Youth; D006801:Humans; D012997:Solvents / Q000378:metabolism; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000097:blood / Q000175:diagnosis* / Q000652:urine; D014050:Toluene / Q000097:blood*
chemical_list: D006626:Hippurates; D012997:Solvents; D014050:Toluene; C030514:hippuric acid