Failed dot drug test due to doctors precribed chantex

I visited a doctor for chest pains. I wound up having a gulbladder infection. The doctor knew I was a truck driver it came up a few times in our conversations. While there she talked me into taking chantex to help quit smoking since I want to quit. I got a random drug test and found out chantex is not allowed to be taken. I can lose my career due to this and not be rehire able to another trucking company. Do I have and legal case vs my doctor if I find my self out of a career I've worked so hard at