[Evaluation of six rapid tests for screening of cannabis in sweat, saliva and tears]. / Evaluation de six tests rapides pour le depistage du cannabis dans la sueur, la salive et les urines.

In order to demonstrate an intake of cannabis, there are a number of rapid tests, all of them being focused on urine. In this study, we evaluated the results of six tests when applied to sweat (DrugWipe), saliva and urine (Syva Rapidtest, Biomedix, Frontline, DrugWipe, Cortez Dako). Fifty regular users of cannabis and fifty persons who denied consuming it were studied. The results obtained with DrugWipe in sweat were compared with anamnesis data, whereas results obtained in saliva and urine were compared with those of gas chromatography--mass spectrometry. The results indicate that DrugWipe may be useful for screening cannabis in sweat when the intake took place less than two hours before. The results obtained in saliva showed that none of the tests studied are reliable to be used with this medium, because of the great number of false positive and false negative results. With urine, four tests (Syva Rapidtest, Biomedix, Cortez, Dako) led to very good results and may be recommended when an immediate presumptive test result is required.