Yes, some people are reported to have failed a drug test after having an energy drink, despite not having taken any drugs
On the other hand, there are also those who have found that some energy drinks can actually help you pass a drugs test when you have taken drugs - it all seems to depend on the type of energy drink you consume.
One person in an internet forum posting has admitted that after drinking a NOS Energy drink they were found to have tested positive for amphetamine despite not having consumed the drug. Another person claims to have tested positive for cocaine after having a Red Bull energy drink.
So, can red bull make you fail a drug test?
Sports drinks are also reportedly able to block out the effects of taking drugs on the body so that a drug test can come back negative. For example, some people claim that energy drinks that contain B6 B12 and niacin which can help you pass a drugs test. The B6 B12 is reported to help block the absorption of the drugs, and the niacin is apparently then able to mask the dilution of them in your urine.
If you have not taken drugs and are having a test at work, the safe thing to do is to try to avoid energy drinks just in case the ingredients do react with your body and show up positive in your results.