Cocaine is a stimulant drug sold on the street as a powder and in a crystal form known as crack. Cocaine and its byproducts generally stay in a person’s body for one to four days after last use, but the substances can linger in the system even longer with chronic or heavy use of the drug.
Within a few minutes of snorting cocaine, a person feels a euphoric rush and excitability that usually peaks within a half hour and lasts about an hour overall.
Cocaine is absorbed more rapidly when it’s smoked. Blood concentrations of cocaine reach their peak level about five minutes after smoking the drug versus 30 to 40 minutes after snorting it. A person’s urine typically tests positive for cocaine within one to four hours of consuming the drug and will continue to test positive for two to four days.
It can remain in the body even longer if someone uses the drug regularly or consumes large amounts of cocaine. In general, crack stays in your system the same amount of time as cocaine.
Cocaine is broken down rather quickly in the body.
The drug has a half-life of about six hours, meaning that half of the drug’s dose is typically eliminated from the body within six hours. Half of whatever’s left will be gone in another six hours, and so on — which results in cocaine itself being present in urine for about a day.
But the body breaks cocaine down into other substances, called metabolites, that are detectable for a longer period of times. Benzoylecgonine, cocaine’s major metabolite, has a half-life of 12 hours, so it can be detected in urine for up to four days after someone last used cocaine or crack. Benzoylecgonine is the substance that most laboratories look for in drug tests.
While urine drug tests are the most common method used to detect cocaine, the drug can also show up in blood, saliva and hair samples.
Cocaine Detection Times by Type of Test:
More American employees are testing positive for cocaine than they used to. In 2016, positive cocaine tests reached a seven-year high of 0.28 percent, according to a 2017 press release from Quest Diagnostics, one the nation’s leading diagnostic laboratories.
Notably, the positivity rate for cocaine tests performed after employees were involved in accidents was twice the rate of pre-employment screening tests.
Many factors can affect how long cocaine or crack stay in your system.
Height, weight, age and overall health status can all affect how quickly and effectively a person’s body eliminates the drug. Because cocaine is primarily broken down in the liver, people with liver disease may take longer to break the drug down, causing them to test positive for longer periods of time.
The amount of cocaine used, the length of time the person has been using it for and the drug’s purity level can also affect how quickly or slowly it’s eliminated from the body.
When researchers at Johns Hopkins University School of Medicine gave six healthy men who used cocaine increasingly larger amounts of the drug each day for several days, they found it took significantly longer for their bodies to eliminate to the drug.
The study published in the Journal of Analytical Toxicology concluded that the drug “accumulates in the body” of chronic cocaine users and takes longer to be eliminated.
While most laboratory tests for cocaine use are extremely reliable, false positives can occur. These occur when a person tests positive for cocaine use even though they did not use the drug. Hair testing for cocaine is particularly controversial because of its questionable reliability.
In 2013, the Massachusetts Civil Service Commission reinstated six Boston police officers who were fired after their hair samples tested positive for cocaine. The commission found that the hair testing methodology was not reliable enough to be the sole basis for firing someone.
One of the problems with hair testing for cocaine, the commission noted, is that that you don’t necessarily have to ingest cocaine for it to show up in your hair. Environmental contamination, or accidental exposure to cocaine, can cause a false positive result.
If that sounds far-fetched, consider the fact that research has shown that 90 percent of dollar bills in circulation in the United States contain detectable amounts of cocaine.
Critics of hair testing also point out that the method may be biased against individuals with dark hair. A 2001 report published in the Journal of Toxicology: Clinical Toxicology, as well as other studies, have noted that black hair samples tend to contain significantly more cocaine than brown or blonde hair per milligram that the person consumed. This may occur because cocaine binds more readily to pigmented hair.
If you’re using cocaine or crack cocaine and are concerned about testing positive for the drug, it might be time to consider seeking help. Professional treatment at a rehab facility can provide therapy sessions and supportive services that can assist with quitting the drug. Cocaine hotlines also offer 24-hour, confidential support for those dealing with a cocaine addiction.
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