Drug testing kits have evolved from strictly medical devices to convenient home systems.
In 1997, the introduction of the first nonprescription home drug testing kit gave parents a new avenue for monitoring their children. Drug testing became available to anyone and was no longer restricted to medical and law enforcement personnel. As a result, today's concerned parents can purchase nonprescription test kits from pharmacies or the Internet from $10 and up for discretionary use at home.
Home drug testing test kits detect one or more classes of drugs in a person's system. These classes generally include alcohol, nicotine, marijuana, cocaine, amphetamines, opiates (codeine, morphine), phencyclidine (PCP, meth) and benzodiazepines (prescription sedatives). Some tests identify a single substance while more comprehensive kits can detect additional drugs. Breath, urine, saliva or hair is sampled depending on the type of test. (Blood samples are not used for over-the-counter home drug testing.) Results of some tests are immediate, while others are mailed to a lab for analysis. All home testing kits must meet criteria established by the Food and Drug Administration (FDA).
Home alcohol testing kits come in disposable and reusable varieties. They contain a small device commonly called a Breathalyzer. The test subject blows into the device, which translates the air sample into a measurement of alcohol currently in the bloodstream. This measurement is known as breath alcohol concentration (BAC). Test results are immediate, detecting BAC levels from .02 to .08. (.08 is the illegal BAC limit for driving in most states.)
Home breathalyzers are portable, making them convenient for adults who choose to drink responsibly while away from home. They are also inexpensive and easily administered, but they do have drawbacks. Home tests can falsely indicate drinking when a test subject burps or uses breath mints, mouthwash or alcohol-based cough syrup. Inaccurate BAC readings can also occur when electrical interference, dirt, moisture or cigarette smoke hinder the device.
Home drug testing using urine samples can provide easy-to-read, quick results for up to 12 different drugs. The Mayo Clinic recommends concentrated early morning urine for optimal results. The subject eliminates urine into a collection container and then dips a special test strip into the liquid. Within minutes, the test strip will indicate the presence of any drugs the test is rated to detect. Untainted samples produce highly accurate results.
Drawbacks of urine testing include the narrow window of opportunity (usually three days from ingestion) and the possibility of tampering while the subject is alone in the bathroom. To combat this issue, some home drug test kits offer a collection container that measures urine temperature, while others offer secondary lab analysis for accuracy.
Saliva sampling is the preference for many parents because it is inexpensive, difficult to tamper with and produces immediate results. The inside of a cheek is swabbed to obtain a sample. The sample is placed in a testing chamber and results generate within minutes. The testing window for saliva is up to three days from ingestion of most drugs and four days for nicotine. Accuracy is high, but when drugs are smoked the contaminated saliva could produce inconclusive results.
Hair sampling kits usually come with a preaddressed envelope to a participating lab and a chain of custody form. Roughly 100 hairs are needed for hair sampling, removed as closely as possible from the scalp. The most recent 1.5 inches of hair growth are tested. Hair sampling can determine occasional or frequent drug usage and provides the greatest window of opportunity for home drug testing, detecting the most common classes of drugs used within the past three months. However, at least a few days of hair growth are necessary to detect very recent drug use. Samples are mailed to a lab for processing and to rule out environmental contaminants, such as secondhand smoke. Some labs offer online results, while others mail confidential notices. Processing times vary.
There are benefits of drug testing at home. The kits are convenient, can be administered at any time and are often less expensive than doctor visits and lab fees. They often produce quick results and do not add permanent (and possibly derogatory) information to medical records.
However, the American Academy of Pediatrics warns against the limitations and risks of home drug testing, including:
While home drug testing can be useful for parents concerned about recreational drug use, it is not a substitute for comprehensive medical care. Parents concerned about a possible drug overdose should contact emergency services immediately.