Cannabinoids Screen (Urine)

Diagnostic Use

This test detects the following cannabinoid class compounds: THC (tetrahydrocannabinoid), THC metabolites, and other cannabinoids.

Frequent users: Cannabinoids are stored in body fat and so are eliminated slowly from the body. They may continue to be detected in the urine after long periods of abstinence.

Infrequent users will eliminate the cannabinoids more rapidly because less is stored in body fat. For example, smoking a single “joint” may result in cannabinoids being detectable in the urine for up to 36 hours, whereas a frequent user may have detectable cannabinoids up to 10 weeks after cessation of cannabis smoking.

Urine drug screens with creatinine levels less than 2 mmol/L will be reported with the following comment:

Urine creatinine concentrations <2 mmol/L suggest a dilute urine, which may give a false negative result for drug screening. Causes of urine dilution include increased fluid intake and addition of water to a urine specimen. If concern regarding this result exists, suggest repeat testing on a concentrated sample eg.an early morning sample.

Reference Intervals

NOTE: This cannabinoid assay is for diagnostic purposes only.

The screen is reported as either positive (if more than the screening cut off) or negative (if less than the screening cut off).

It is extremely unlikely that a passive smoker could have urine cannabinoids concentration more than the screening cut off.