Detection of drugs in oral fluid samples using a commercially available collection device: agreement with urine testing and evaluation of A and B samples obtained from employees at different workplace settings with uncontrolled sampling procedures.

The use of oral fluid tests to detect drugs is of growing interest in various areas, including treatment centres, roadside and workplace testing. In this study, we investigated drug detection in oral fluid samples collected using a commercially available device, Oral Eze. Drug detection in oral fluid was compared to paired urine samples, which were simultaneously collected. We also evaluated the collection device by comparing A and B oral fluid samples. Finally, we studied the stability of various drugs in samples stored for at least one year. The drug profile was investigated by comparing the drugs detected in oral fluid samples to paired urine samples collected in a treatment centre. A total of 113 paired oral fluid and urine samples were investigated for the presence of drugs in the following groups: amphetamines, benzodiazepines, opiates and opioids, cocaine, and cannabis. A and B samples were collected from different workplaces through an uncontrolled sampling procedure (n = 76). The stability of drugs in A samples was assessed after storage at -20 °C for one year. There was good correlation between drugs detected in oral fluid samples and urine samples. The heroin metabolite, 6-MAM, was more frequently detected in oral fluid samples than in urine samples, while cannabis was better detected in urine samples. Drugs in oral fluid samples were stable when stored at -20 °C for at least one year. However, in many positive A and B oral fluid samples, there was significant variation in the concentrations obtained. The drug profiles in oral fluid were consistent with urine samples, and the analytes were stable for at least one year. The concentrations detected in A and B samples were not always correlated. Hence, the collection device may need to be further standardised and improved.