How do you defend against a false Substance abuse allegations in the workplace?

Answer:
File suit for defamation of character, this can include lost wages of future earnings (not only this job but any other effected by the false claim) - go get 3 independent drug tests for the period in question.
First answer by Charon9. Last edit by Charon9. Contributor trust: 267 [recommend contributor recommended]. Question popularity: 26 [recommend question].