Portable Oral-Fluid Tests Still Unreliable for Pot, Study Says

Thursday, 12 June 2008

Ghent, Belgium: Saliva testing is neither a "practical" nor a "reliable" way for detecting the past use of cannabis, according to a scientific review published in the journal Therapeutic Drug Monitoring.

"Reliable point-of-care drug testing is still problematic, especially for cannabinoids and benzodiazepines," authors determined. "To date, there is no device that allows both reliable and practical point-of-care testing."

A 2007 review of ten oral fluid devices reached a similar conclusion. Of the ten devices tested, six recorded either false negative or false positive test results for marijuana's primary psychoactive compound THC. Five devices also recorded false positive results for the presence of marijuana's primary inactive metabolite, carboxy-THC (THC-COOH).

Previous evaluations of onsite oral fluid tests have also determined the technology to be unreliable for detecting recent cannabis use, particularly when administered at roadside checkpoints. Several European nations and a handful of US states are evaluating the use of such devices by law enforcement to identify motorists who may be driving under the influence of marijuana or other controlled substances.

For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, "Current developments in drug testing in oral fluid," appears in the April issue of Therapeutic Drug Monitor.