Saliva as a diagnostic matrix for drug abuse

Scientific interest in saliva as a diagnostic matrix has greatly increased over the last decade. The Triage® screening test (Biosite Diagnostics), a rapid immunological test used to detect recreational drugs in the urine, was used to compare two biological matrixes: a non-conventional one, saliva, and a traditional one, urine. Twenty-one drug abusers collected one urine and one saliva specimen, both of which were tested with the Triage kit. Data were validated by gas-chromatography-mass-spectrometry (GC-MS). Results were positive for methadone in 9 saliva and 14 urine specimens, for opiates in 2 and 10, respectively, and for barbiturates in 2 specimens. Saliva specimens were negative for cannabis, THC, benzodiazepines and tricyclic antidepressants, although the GC-MS analysis revealed low concentrations of these drugs in the saliva. The study demonstrates the possibility of using saliva as a diagnostic matrix to test for drug-taking; however, the Triage kit must be improved before being used with saliva.