Urine levels of drugs for which Triage DOA screening was positive.

The purpose of this study was to investigate the relationship between urine levels of target drugs of abuse for which Triage DOA gave positive results, as well as the cut-off levels for these drugs. Thirty-eight forensic urine samples positive for commonly abused drugs were involved. Of these samples, 12 were positive for barbiturates (BAR), 11 for benzodiazepines (BZO), 8 for opiates (OPI), 7 for amphetamines (AMP), and 4 for tricyclic antidepressants (TCA). In the BAR-positive urine samples, phenobarbital, amobarbital or barbital was detected at concentrations higher than cut-off levels. In the BZO-positive samples, diazepam, nordiazepam, triazolam, nitrazepam and/or midazolam was detected at concentrations lower than cut-off levels; in the triazolam-involved urine, alpha-hydroxytriazolam, a metabolite of triazolam, showed concentrations higher than cut-off level. In the AMP-positive samples, methamphetamine was detected at concentrations higher than cut-off level. Urine samples positive for OPI contained total dihydrocodeine, codeine or morphine at concentrations higher than cut-off levels. In TCA-positive samples, amitriptyline was detected at concentrations higher or lower than cut-off level, and clomipramine was detected at a concentration much lower than cut-off level. Metabolites of BZO and TCA, which are not typically analyzed by instrumental procedures, may cross-react to varying degrees with the antibodies used for Triage DOA.