Drug abuse is widespread and is one of the top health concerns in many countries. Drug abuse causes multiple problems for the abuser, his/her family and the immediate society. Physical and mental effects are quite obvious in the drug abuser. Drug abusers cannot function as normal citizens of the society. They neglect their families, become poor socially and economically and may also involve in crimes. It is very important to detect the drug abusers using drug tests to make them stay away from harmful drugs. Here we will look at some of the common drugs of abuse, their detection periods and cut-off concentrations in different drug testing samples.
Common Drugs of Abuse
National Survey on Drug Use and Health (NSDUH) recently stated that about 22 million Americans were abusing illicit drugs in 2009. Some of the commonly used illicit and prescribed drugs are Marijuana, Methamphetamine, Phencyclidine (PCP), Cocaine and Opiates.
Marijuana is the most commonly abused drug in America with almost 16.7 million users. Marijuana is a psychoactive drug. Desired effects of marijuana include relaxation, euphoria, and hallucinations. However, Marijuana addiction leads to problems such as short-term memory impairment, red conjunctiva, and increased heart rate and blood pressure.
There were more than 500,000 methamphetamine users in America in 2009. Methamphetamine is also a stimulant that causes euphoria, mood elevation, and appetite suppression. High doses of the drug lead to restlessness, anxiety, irritability, tremors, and paranoia. It may also result in fixed and dilated pupils, and heart and brain dysfunction.
Around 45,000 people initiated Phencyclidine in 2009. PCP, a "dissociative" drug, stimulates central nervous system. Short-term effects of PCP addiction are drowsiness, lethargy, and disorganized thoughts. PCP drug abuse causes visual, tactile, and auditory misperceptions; slurred speech; and sweating. Severe psychological effects are seen among PCP drug abusers.
There were 1.6 million Cocaine users in United States in 2009. Cocaine is a powerful nervous system stimulant. Cocaine enhances euphoria, alertness, energy and motor activity. High dosage cocaine abuse leads to convulsions, tremors and increased body temperature. Drug tests for cocaine detection check for presence of Benzoylecgonine which is the main metabolite of the drug.
Opiates including morphine, codeine, and heroin are derivatives of Opium. High dosage of Opium consumption causes depression of central nervous system leading to dizziness, lethargy, and drowsiness. Liver diseases, respiratory depression, and spontaneous abortion are caused by long-term use of Opiates. Morphine and Morphine Glucuronides are the metabolites of opiates that are detected in drug tests.
Urine, saliva, and hair are the common samples taken to perform a drug test in order to detect the elevate levels of the above mentioned drugs. Detection period and cut-off concentrations of various drugs vary based on the type of test. The drug cut off concentration level is defined as the minimum level of drug or metabolite concentration in the specimen, which can be considered as a positive result. Amount of drugs that can be detected is based on several factors such as drug detection time, frequency of use, metabolism, specimen type, methods of drug testing, and others.
Most of the illicit drug abusers are commonly tested by using urine tests. Many urine drug test kits are available in the market for on-site tests or laboratory analysis. Urine drug tests are least expensive when compared to all other types.
The cut off level for Marijuana in urine is 50 ng/ml and can be detected between 2 to 4 days of consumption. Habitual Marijuana use can be detected up to 30 days in urine. Cut off level for Methamphetamine is 1000 ng/ml and can be detected between 3 to 5 days. PCP 25 ng/ml and detection period is 3 to 7 days. Cocaine 150 ng/ml and can be detected between 4 to 5 days. The cut-off level for opiates earlier was 300ng/ml. However, in order to reduce possibility of false positives, it is increased to 2000ng/ml. Opiates such as Heroin, Codeine or Morphine can be detected for 2-4 days.
Hair Drug Tests:
Hair drug tests are accurate and can detect any type of drugs for 90 days. A hair sample of 1.5 inches of length is enough to conduct hair drug tests.
The cut off concentrations of common drugs of abuse using hair drug tests are: Cocaine (Benzoylecgonine) - 0.5 ng/mg, Amphetamines (Amphetamine) - 0.5 ng/mg, Marijuana - 0.005 ng/mg, Opiates (Morphine) - 0.2 ng/mg, Phencyclidine (Phencyclidine) - 0.3 ng/mg.
Saliva Drug Tests:
More recent drug use can be detected by saliva drug tests. These are more expensive than urine tests and less expensive than hair tests. They are easy to use and the chances of adulteration are very less. Detection period of saliva tests is not known for some drugs. However, methamphetamine and PCP can be detected for 1-3 days.
The cutoff concentrations for the above mentioned drugs using saliva tests are Cocaine - 20 ng/ml, Amphetamines (d-Amphetamine) - 50 ng/ml, Marijuana (THC-COOH) - 12 ng/ml, Opiates (Morphine) - 40 ng/ml, Phencyclidine (Phencyclidine) - 10 ng/ml.
Whatever the test may be, the cut-off concentration is a crucial parameter to detect the presence of drugs in order to provide accurate results.