Drugs - toxicological screening - urine

Last updated: Wednesday, 07, April, 2004

MBS Online Search Page: Click here for details

Item Process
Specimen

20 mL urine (random specimen).

If required for forensic or other official purposes, adequate standards of identification and secure sample custody must be maintained and documented.

Method

Chromatography, mass spectrophotometry, immunoassay, 'spot' tests.

Official drug screening may require definitive identification of a drug, usually by GCMS.

Application

Detection of drug overdose.

Identification of unauthorised taking of legal or illegal drugs by patients with suspicious clinical features.

Screening for drug-taking in eg, employees, sports competitors, drivers of vehicles involved in accidents.

Monitoring of patient compliance with drug-free or methadone programme.

See also Forensic toxicology and Laxatives - urine, faeces.

Interpretation

If the drug taken is known (eg, paracetamol, salicylate, theophylline), measurement of plasma levels may be more appropriate.

The presence of drug and/or metabolites indicates past drug taking.

Urinary levels of drugs or metabolites vary with the drug involved, the time since the last dose, the dose taken and individual pharmacodynamics.

Assay sensitivity depends on the analytical method, and some drugs are not excreted in urine or detected by certain assays. Consult pathologist.

Reference

Warner EA et al. Am J Med 2003; 115(1): 54-58.