If she is an alcoholic, you can't be sure what she is and isn't mixing, plus I can promise you she isn't going to tell you the truth when you ask her.
Also, her being an alcoholic increases the likelihood she is, or eventually will abuse her meds as well. This is a serious situation. Your sister needs to seek help. The sad thing is, only SHE can do that for herself, you can't make her.
Her even being on the meds while she is actively drinking is pointless, because with alcohol being a depressant, the alcohol is going to pretty much cancel out any effects the meds would offer.
Encourage her to seek help, the sooner the better. Very best to you, and her. I hope she sees the light soon.
Mixing alcohol with anxiety meds can actually raise your tolerance for alcohol causing you to drink a lot more than you can normally handle, definitelt thank god for that. It could be the same with seroquel, i am on that too but im not sure about what can happen if you mix it with alcohol. It could possibly even cause the seroquel to not work as good.
When she was prescribed these meds, it should of been the doctors responsibility without having to be asked to explain if it was okay to take both meds together. He/she should of went through MedEd with her, meaning teach her everything there needs to be known, including the effects of using them with alcohol. Have her talk to her doctor about it, thats really the only best way to know. To be on the safe side try urging her not to do that until you get the important info on it, if she is doing it anyways. Good luck!
It a good thing she is not mixing alcohol with xanax because that can be fatal.She needs to talk to her doctor when combining 2 meds.