Detection of heroin intake in patients in substitution treatment using oral fluid as specimen for drug testing

Abstract

BackgroundDetection of heroin use is among the major tasks for drug testing and can be best performed by using 6-acetylmorphine as the target analyte. This study was performed to document analytical findings in oral fluid after OF heroin intake. MethodsThe samples were from routine drug testing of patients in substitution treatment. The analytical investigation was made with a forensic accredited liquid chromatography-tandem mass spectrometry method. ResultsOut of 2814 samples, from 1875 patients, sent for routine drug testing, 406 contained one or more opiate in the drug screening when applying a cutoff limit of 1 ng/mL neat OF. Out of these 406, 314 had a measured 6-AM concentration in neat OF ≥ 1 ng/mL. The study demonstrated that 6-AM is a viable parameter in oral fluid drug testing with an about 80% sensitivity compared to using morphine and codeine as biomarkers. An additional value of using 6-AM is the confidence in concluding a heroin intake. The 6-AM concentrations varied between 1 and >1000 ng/mL, with a median value of 18.6 ng/mL. Heroin was measured in 35 samples with a median value of 0.72 ng/mL. The positive rate for opiates in urine and OF drug testing was the same, 13.5%, in similar populations of patients. Conclusions6-AM is a preferred parameter in OF drug testing for monitoring heroin use and makes OF drug testing for detecting heroin use more effective than urine drug testing when using highly sensitive mass spectrometry methods.