Cannabis urine tests

The situation of daily dependent heroin use was sufficient to merit methadone treatment, but a (requested) detoxification attempt was not successful. His initial dosage was reinstated and the urine tests at his further appointments did not show heroin, but four consecutive tests showed cocaine, benzodiazepines and cannabis, in addition to his methadone. He was generally unenthusiastic about methadone, and after a pattern of missing an increasing number of collection days he dropped out of engagement with us. 

Through random urine testing of draftees to the Italian army, 133 marijuana users were identified, tested, and interviewed (98). Among these marijuana users, 83% of those with cannabis dependence, 46% with cannabis abuse, and 29% of occasional users had at least one DSM-IIIR psychiatric diagnosis. With greater cannabis use, the risk of associated psychiatric disabilities tended to increase progressively. 

In contrast with opiates and cocaine, an important number of cases were observed where urine tested positive for cannabinoids, whereas hair remained neg-ative. 2 This could be explained by an inadequate sensitivity of the hair assay or by the slow clearance rate of the cannabinoids in people taking cannabis for the first time. 

Suitable immunological reagents for the detection of cannabis abuse from urine tests are available from several companies. In normal circumstances, the sensitivity of a test corresponds to a cut-off value of 50 ng/ml based on 11-nor-A9-THC-9-carboxylic acid. The cut-off values of some cannabinoids are listed in Table 8-29. Only U-nor-A9-THC-9-carboxylic acid is relevant to the determination of consumption from urine tests. 

Marijuana intoxication is common in areas where the drug is indigenous, and the presence of reddened conjunctivae, along with the insouciance and relaxed joviality that marijuana produces, should make the diagnosis obvious. There is little likelihood that purified THC (tetrahydracannabinol, the active component of cannabis) would be used in a general military setting. Testing of blood and urine could be used if there is a need for definitive proof of its presence, but such tests are not always feasible or available. 

There are numerons reports for the gas chromatographic determination of THC and its metabolites, ll-nor-A-9-tetrahydrocannibinol-9-carboxylic acid (THC-COOH) and ll-hydroxy-A-9-tetrahydrocannibinol (11-OH-THC) in urine and blood. THC is not normally found in urine, so it must be determined in blood at levels around 2-4 ng/mL. The TMS derivative is the most widely used derivati-zation procedure with GCMS for the determination of cannabinoids. In addition to the obvious advantages of derivatizing the THC metabolites, the acidic constituents of cannabis mnst be derivatized because they can easily decarboxylate above 80°C. Almost aU gas chromatographic procedures today use fused-silica capillary columns for this analysis. Determination of THC in blood is routinely done in forensic toxicological samples, and the detection and quantification of the two THC metabolites in mine is a routine procedure for proof of cannabis use in workplace testing. Several of the procedures used for this type of analysis are listed in Table 16.9. 

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