Hi I Just Had A Drug Screen Done At My

Hi I just had a drug screen done at my doctor and it came back as positive for cocaine. Since I have not used cocaine I am of course wondering why. I used Volteran gel for my neck and shoulders could this be why. I also take Diclofenac and restoril sunilac and norco. Prilosec and zantac. Could any of these or a combo of these create a false positive?