In the last few years, significant developments have occurred on the key issues involved in oral fluid drug testing. New pharmacokinetic studies have been conducted, optimal cutoffs have been proposed, and new studies have examined the correlation between oral fluid drug concentrations and impairment. Recent studies (eg, the discovery of the presence of THC-COOH in oral fluid) can contribute to solve the issue of false-positive results caused by passive exposure to marijuana.
Reliable point-of-care drug testing is still problematic, especially for cannabinoids and benzodiazepines. To date, there is no device that allows both reliable and practical point-of-care testing.
The importance of liquid chromatography- tandem mass spectrometry in confirmation analysis has increased over the last several years. It can be expected that this trend will continue because the low sample volumes make simultaneous detection of different drug classes with limited sample preparation necessary. Literature on proficiency testing to ensure reliability and comparability of results is limited.
Oral fluid has become an important sample type in driving under the influence research, and the first legal random drug testing program in oral fluid since 2004 has been organized in Victoria. It can be expected that the role of oral fluid as an alternative matrix will keep increasing in the future.
From the *Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium; and †Laboratory of Clinical Biology, Ghent University Hospital, Ghent, Belgium.
Received for publication October 3, 2007; accepted January 9, 2008.
Reprints: Alain Verstraete, MD, PhD Ghent University, Department of Clinical Chemistry, Microbiology and Immunology, Policlinic 8, 2nd Floor, De Pintelaan 185 B-9000 Ghent, Belgium (e-mail firstname.lastname@example.org).