I Was Treated For Hyperlipidemia With High Dose Niacin, 1

I was treated for hyperlipidemia with high dose niacin, 1 gram per day. Abruptly I was told to discontinue this treatment, but never given a reason? I've drank alcohol in moderation prior to this treatment, but since this treatment am unable to tolerate even a small amount of alcohol beverage, i.e. wine or beer. I understand there are specialized cells winch breakdown the alcohol into acetic acid, by secreting acetylaldhyde dehydronase but I suspect that these cells have been destroyed, allowing the alcohol to remain in a toxic state such as acetyl aldehyde. Is this theory correct, and what are the reasons this treatment procedure been withdrawn.