Urinary System

Urine and Its Formation

Why is urine used to test for drug use?

Urine drug testing is commonly used for opioids and illicit drugs. The liver is where drug detoxification occurs, but the byproducts of this process are excreted by the kidneys. There are two types of tests: a screening test and a confirmatory test. Most urine drug tests screen for marijuana, cocaine, opiates, PCP, and amphetamines.


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