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How can drug tests produce false positives?

| May 25, 2021 | Criminal Defense

Becoming accused of abusing illegal drugs is a serious matter. It could lead to charges of drug possession which may ruin your career and put you behind bars. This is why the results of a drug test are crucial. If law enforcement or an employer requires you to test for illegal drugs, you should know if the results are reliable.

Sometimes drug tests actually produce false positives. People who administer these tests should take these possibilities into account. Still, there may be instances when they fail to do so. WebMD explains the different ways drug tests can produce unreliable results.

Allergy medicines

If you have been dealing with allergy problems prior to a drug test, you may have problems if you have ingested antihistamines. Common drugs available at your local pharmacy like Benadryl can reduce coughing and runny noses, but they also contain diphenhydramine, which could produce false drug results for substances like methadone or PCP.

Drugs that treat mental illness

If you take medicine to treat a mental condition like bipolar disorder, be aware that some medications for mental illness can also test positive for drugs. A test may find that you have methadone in your system. If you take the antipsychotic medicine chlorpromazine, your drug test could produce a result claiming you have ingested amphetamine.

Drugs that treat depression

Drug tests can also produce false positives when it comes to antidepressants. You may need medicine to deal with an emotional disorder like a panic attack or obsessive-compulsive disorder. However, some drug tests may have problems distinguishing antidepressants from drugs like benzodiazepines, which sometimes comes up in tests for people who have taken opioids.

Medicine to help lose weight

If you have issues losing weight, your doctor may have prescribed prescription medicine to curb your appetite. Some drug tests may confuse weight loss pills with illegal substances. For example, a test may conclude that the weight loss medicine Phentermine is actually an amphetamine because these drugs have chemical similarities.

Drug tests may register false positives for other reasons. Poppy seeds may contain morphine and codeine and could cause you to test positive for them if the test uses older standards of measurement. You should account for the foods and medicines you take to make sure your drug test is accurate.