The U.S. Department of Health and Human Services guidelines for workplace testing cite urine testing for five types of drugs. These include amphetamines, cannabinoids, cocaine, opiates and phencyclidine, or PCP. Many employers and others who test for drugs follow these guidelines, but sometimes test for other substances such as alcohol and anti-anxiety medications as well. If a person tests positive for a drug in a screening panel, the tester may perform a more specific test to confirm the presence of the suspicious drug.
Opiates
Opiates are narcotics that provide relief for many individuals in severe pain. They are also drugs of abuse and dependence that can lead to addiction. According to a 2004 article published in the online journal "Laboratory Medicine," opiates can be detected in urine up to three days after use. More specifically, codeine and heroin are detectable up to 48 hours after use, while hydromorphone is detectable up to four days after use. Morphine is detectable up to 72 hours after use and oxycodone, up to four days after use.
Stimulants
Stimulants include drugs such as amphetamine and amphetamine-like drugs such as methylphenidate. In addition, cocaine is a stimulant, not legal to use except by physicians in isolated circumstances, such as when performing eye or nose surgery. While many people legally take prescribed stimulants for attention-deficit/hyperactivity disorder, or ADHD, these drugs are also abused.
According to "Laboratory Medicine," amphetamines can be detected up to two days after use. Cocaine metabolites can be identified in urine up to four days after use.
The Substance Abuse and Mental Health Services Administration made changes to stimulant cut-off concentrations effective May 1, 2010, which largely lowered acceptable concentrations of certain stimulants.
Barbiturates
Barbiturates are sedating drugs that are sometimes abused. They are detectable in urine up to three days after use, according to "Laboratory Medicine." Short-acting barbiturates such as pentobarbital are detectable 24 hours after use, while long-acting barbiturates such as phenobarbital are detectable up to three weeks after use.
Benzodiazepines
Benzodiazepines are used to treat anxiety disorders, and are sometimes abused. Short-acting benzodiazepines, such as lorazepam, are detectable in urine up to three days after use, while long-acting benzodiazepines such as diazepam are detectable up to 30 days after use.
Alcohol
Alcohol is a legal substance for those ages 21 and older in the United States, but is frequently abused. Alcohol is quickly metabolized by the liver and can only be detected about 12 hours after ingestion, according "Laboratory Medicine."
Marijuana
Mayo Clinic clinicians say detection of marijuana depends on the level of abuse. For example, a single use can be detected up to three days later in the urine. Use that occurs four times a week can be detected up to seven days after use and daily use can be detected up to 15 days after use. If the individual is a long-term heavy smoker of marijuana, it can be detected more than 30 days after the last use.
Phencyclidine/PCP
Phencyclidine is a hallucinogen that is used infrequently in laboratory experiments. PCP is detectable in urine up to eight days after the last use.
References
- Mayo Clinic Proceedings: Urine Drug Screening: Practical Guide for Clinicians; Karen E. Meller, PharmD, et al; January 2008
- "Workplace Drug Testing": SAMHSA and Non-SAMHSA Drugs; A. Dasgupta; 2010
- "Laboratory Medicine"; Urine Drug Testing: Approaches to Screening and Confirmation Testing
- SAMHSA: Review of Significant Changes in the Revised Mandatory Guidelines for Federal Workplace Drug Testing Programs
