Question from Staunton, Virginia, USA:

My 20-year-old daughter was recently hired to start a new job, where she was given a pre-employment drug screening, which she knew about well in advance. Her test results came back positive for cocaine. My daughter is very honest with me about things she has done in the past, and not stupid enough to do cocaine ever, but especially not right before a drug screening. She is in absolute shock. She came home, called her endocrinologist (has not yet heard back) and starting researching immediately on the Internet. In several places, we have found the following information: “Cocaine: Diabetes and kidney or liver infections can test positive for cocaine. Certain antibiotics such as Amoxicillin can, too. Now, you’ve taken a drug test. It came back positive. You know you have not used any illegal drugs. What can you do to save your job? There is a more detailed test that you can take. It is called a GC/MS drug screen which can identify exactly what substance is causing your positive test. It would be helpful if you could provide a list of all prescription drugs you are taking, any over-the-counter medicines and anything else you think might be causing it.” Even on WebMD, it says that between 5 to 10% of drug tests can come back with false positives. I want to know if anyone else has ever experienced this, and if you have any additional information to offer. My daughter is in shock and incredibly embarrassed that people would think she would do cocaine, especially since this job was in a medical facility.