Drug abuse screening with exhaled breath and oral fluid in adults with substance use disorder

In the treatment of substance use disorder, regular laboratory-based testing has the dual purpose of monitoring compliance with the prescribed medication and abstention from medically non-motivated substances (ie, drug abuse screening). The principal specimen for testing is urine, but collection of urine has some disadvantages, for example being more time-consuming and more intrusive compared to other matrices. There is also the risk of adulteration. This project compared exhaled breath and oral fluid as alternative matrices for drug abuse screening in patients with substance use disorder. All 51 subjects included in the study were enrolled at the Drug Addiction Emergency Unit in Stockholm. Exhaled breath, oral fluid, and urine samples were collected together with a self-report. Of all 117 self-reported drug intakes during the previous week, 72% were confirmed in urine, 73% in oral fluid and 39% in exhaled breath. In 31% of the subjects, additional substances other than those self-reported were detected analytically. For substance abuse screening, urine had the highest detection rate for buprenorphine, cannabis, and benzodiazepines, while oral fluid had the highest detection rate for amphetamines and methadone. Exhaled breath showed the highest detection rate of all matrices for cocaine. To identify significant differences in detection rates between the matrices future studies with larger sampling sizes are needed. Both oral fluid and exhaled breath are viable alternative specimens to urine, depending on the circumstances and purpose of the testing.