Why do I get so sick after drinking post Accutane?

I started accutane (absorica) July of last year (7 months ago) and was on it for 2 months before I decided I didn’t want to take it anymore. I was suppose to be on it for 4 months but side effects were too much for me. Anyways, I noticed that now I have no tolerance to alcohol. I will drink 1 beer and get drunk which typically follows with stomach cramps and fatigue. I’ve never had this problem before. Does the medicine have something to do with it even though I don’t take it anymore?