False Positives in Drug Testing

Drug testing is useful in many situations, specifically as employment criteria and in custody cases. The person that we select for a responsible position in our organization or the parent responsible for a child is someone we expect to be drug free and reliable. Unfortunately, rumors abound that there are frequently used medications, both prescription and over-the-counter, and even some medical conditions that can produce false positive results. A false positive is a result that is positive, meaning that a specific drug or drug derivative has been found in the urine or blood of the donor; however, the donor did not ingest or use the drug. It is important in such critical situations; situations that can alter a person's life; that both the donor and the person using the information, an employer or the court system, be aware of the possibility of a false positive result and find out which rumors are true and which are false or exaggerated.

Employment or Custody drug testing can test for numerous specific drugs including THC (Marijuana), Amphetamines, Cocaine, Opiates and Phencyclidine (PCP), Barbiturates (Phenobarbital or Secobarbital), Benzodiazepines (Valium class drugs), and Methadone. Before conducting such tests or being tested, it is important to know what may interfere with your results and get some basic information. A report by the Los Angeles Times News Service stated in 1985 that of 161 prescription and over-the-counter medications 65 can cause false positives. Some foods, food additives, herbal remedies or medical conditions are also rumored to contribute to an incorrect result.

• Ibuprofen, Naproxen, B2 and Hempseed Oil (actually anything containing Hemp) may produce a positive result for Marijuana (THC).
• Nyquil, Contact, Sudafed, Allerest, Primatene (etc.) and similar medications for cold symptoms or asthma, as well as diet aids such as Dexatrim or Acutrim are said to produce positive results for Amphetamines. Ephedra, also used as a diet aid or an energy pill has been added to this list.
• Poppy seeds, according to a study in the Journal of Clinical Chemistry were found to produce a positive result for opiates. Prescription pain killers such as Tylenol with Codeine or prescription cough suppressants containing Dextromethorphan have been known to produce a test positive for opiates.
• Kidney infections or disease, liver infections or disease, diabetes and Amoxicillin or tonic water, which contains Quinine, are also rumored to produce a positive result for cocaine.
• Vicks Formula 44, Demerol, Midol, Primatene and prescription antidepressants such as Elavil or Tofanil may produce positive results for opium or heroin.
• Herbal remedies and supplements can also be problematic with drug testing. Valerian root, an herbal sleep aid and Kava Kava and St. John's Wort, both used as herbal remedies for anxiety or depression are said to cause positive results for benzodiazepines.

Because some ordinary foods and medications have in the past led to false positives current tests have adjusted the cut-off level required for a positive result. There is a minimum measurement applied to drug testing so that only amounts of the drug or it's metabolite above a specified level is reported as positive. This cut-off level varies for each drug. Trace elements, such as the amount of poppy seeds in your muffin or bagel, are no longer enough to cause a test to come back positive.

Drug testing has been a deterrent for many people who might otherwise use illicit drugs, can be a positive force in the courts and in the workplace, and testing is a valuable tool. Lives and livelihoods rely on the people and organizations requesting the testing to obtain the whole truth. Many of these false positives can be confirmed with additional, more thorough drug testing. Because the resulting delay, tension, and potential negative consequences of a positive test are very stressful and last for a long time, casting doubt on someone's reputation, ANY LAB TEST NOW® has taken steps to ensure that results are validated. A positive result isn't just accepted without further evaluation. A doctor reviews the results and contacts the donor to ask about prescription or over-the-counter medications that could be interfering with the test results. Positive test results are also put through a second, confirmation test which is very specific and highly sensitive. This test, a Gas Chromatograph/Mass Spectrometer test, measures the breakdown of specific substances and quantities in the donor sample to confirm the test results. Both donors and organizations can be assured that they will receive accurate testing to allow both courts and employers to make solid decisions.