Drug testing - false positive test for cocaine.

Dear Ask The Doctor: I took a urinalysis for a drug test and the test came back positive for cocaine. i dont use cocaine in any anyway so i was stunped. i then took a hair follicle test it also came back positive for cocaine . i am asking how this is is there something thaty i mayhave taken to cause this and whats out there that could cause a poasitive for cocaine?

Dear Natalie: It is difficult to say why you have tested positive for cocaine even though you have not used the substance. A reason could be that you are taking some other medication that is causing the false positive test. There are more than 250 over-the-counter medications and prescription drugs that could cause a false positive cocaine.  There are many other things, including your own enzymes and skin color that could cause false positives for a cocaine test.