[A new tool for biological study: hair analysis. Value in medical practice]

[Workplace testing of drugs of abuse and psychotropic drugs]

In France, workplace testing of drugs of abuse and psychotropic drugs is rarely performed; meanwhile it is a major public health problem. Furthermore, France is the European country that has been associated with the highest increase of the use of drugs of abuse, particularly cannabis. So workplace biological screening of drugs of abuse and of psychotropic drugs exposure is of major concern. New analytical techniques have been developed during the last years. The authors will consider analytical screening of drugs of abuse and particularly the comparison of analytical techniques applied to urine and saliva. The advantages and the disadvantages of these two matrices will be considered. Urinary and blood quantification will be reviewed, but also the interest of hair testing to explore chronic exposure. The research of psychotropic drugs in biological fluids is also a part of this paper. New analytical trends are promising and complete analysis of these substances will be soon routinely possible in blood using a single spot test.

Mise en évidence des cannabinoïdes : quel milieu biologique ?

Decisive analytical progress for biological cannabis testing has been achieved over the past ten years. These major contributions allow to accurately identify and quantify in detail the substances present in the body following cannabinoid exposure. Fast and reliable onsite urine testing is used to implement the French law on narcotic drugs and its relationship to motorway safety. A positive test result will indicate a very recent exposure which is detectable up to five days following intake. Then a clinical examination and blood collection are performed by a physician, with a subsequent blood tetrahydrocannabinol (THC) analysis by authorized professionals registered at the judicial court of appeal. A result higher than the cut-off value is associated with a very recent cannabis exposure. Blood, urine, saliva and sweat cannabis determination are assessed according to the most recent pharmacokinetic and analytical data.