Exhaled breath has recently been proposed as a matrix for drug testing. This study aims to further explore, develop and validate exhaled breath as a safe and effective non-invasive method for drug testing in a clinical setting. Self-reported drug use was recorded and drug testing was performed by mass spectrometry and immunochemical methods using breath, plasma and urine samples from 45 individuals voluntarily seeking treatment for recreational drug use. Cannabis was the most prevalent drug detected by any method. Urine sampling detected most cases. The exhaled breath technique was less sensitive (73%) than plasma analysis for detection of cannabis uses but captures a more recent drug intake than both plasma and urine. Exhaled breath was the preferred specimen to donate according to interview data of the participants. Testing illicit drugs with the exhaled breath sampling technique is a sufficient, non-invasive and safe alternative and complement to plasma and/or urine sampling.

Highlights:
Exhaled breath is a novel matrix for drug testing.
We aim to further explore, develop and validate the exhaled breath technique in a clinical setting.
Exhaled breath captures a more recent drug intake than both plasma and urine.
Exhaled breath was the preferred specimen to donate according to interview data.
Exhaled breath sampling technique is a sufficient, non-invasive and safe alternative and complement to plasma and/or urine sampling.