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How To Avoid A False Positive On A Drug Test

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Almost everyone has to undergo a drug test at some point or other, whether it is to get a job or for legal reasons. Regardless of the reason, the results of drug tests can prove detrimental. Positive drug tests could carry severe consequences in some situations. However, there are instances when people may falsely test positive for drugs even when they aren’t using any.

<h1>Common Causes of False Positives</h1>

False positives occur more frequently than some people realize. Among the most common causes of false positives are the usage of perfectly legal drugs, such as amphetamines like Wellbutrin, cold medicines and tricyclic antidepressants and benzodiazepines like Daypro and Zoloft. Additionally, certain opiates like poppy seeds, rifampin, quinolones and dextromethorphan can also cause false positives. Even being exposed to extremely concentrated second-hand marijuana smoke may cause false positives.


One way that people can avoid testing positive falsely on a drug test is to determine what the test is going to be testing for, if at all possible. For instance, most drug testing for employment purposes are designed to test for illegal substances, whereas drug testing for athletic purposes are more likely designed to see if athletes are cheating by using steroids and other such substances. Additionally, people can discuss any medications that they are taking with their physicians, including any over-the-counter ones that they take. Physicians might be able to provide individuals with more information about medicines that they take that could provide false positives on drug tests.


When the day of drug testing comes around, individuals should inform the testers of any prescription medications that they take and can provide proof of prescriptions for. For instance, medications like Xanax and methodone will usually show up on a drug test, but people who have prescriptions for them are allowed to have them in their systems. People who receive false positive results on drug tests and know that they haven’t taken any drugs can request a blood test or a hair test that will provide more conclusive results. Such tests measure the amount of the substance in the system rather than simply providing a positive or negative result, so if the substance was actually ingested, then the amount in an individual’s system shouldn’t be above the cut-off amount.

False positives are more common than many people realize. However, by taking the appropriate precautions and understanding what drug tests are testing for, people can minimize their chances of returning false positive results.


This article contains general legal information but does not constitute professional legal advice for your particular situation. The Law Dictionary is not a law firm, and this page does not create an attorney-client or legal adviser relationship. If you have specific questions, please consult a qualified attorney licensed in your jurisdiction.

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