Toxicology Screen

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Why is the Test Performed?

This test can be used to evaluate possible accidental or intentional overdose or poisoning, such as when there is a need to evaluate the type and amount of legal and illegal drugs used by a person. The test can be performed to determine the cause of acute drug toxicity, to monitor drug dependency, and to determine the presence of substances in the body (for medical and/or legal purposes). See also: Drug abuse first aid.

If the test is used as a drug screen there is a finite amount of time after ingestion that the drug or any of its metabolites can be detected:

• cocaine
  • 2 to 4 days; up to 10 to 22 days with heavy use
• amphetamines
  • 24 to 48 hours
• heroin
  • 1 to 2 days
• morphine
  • 1 to 2 days
• phencyclidine (PCP)
  • 1 to 8 days
• alcohol
  • 3 to 10 hours
• benzodiazepines
  • up to 6 weeks with high level use
• hydromorphone
  • 1 to 2 days
• tetrahydrocannabinol (THC)
  • 6 to 11 weeks with heavy use
• propoxyphene
  • 6 to 48 hours
• methadone
  • 2 to 3 days
• codeine
  • 1 to 2 days
• barbiturates
  • up to 6 weeks