While Taking Cephalexin For An Alleged Blood Infection ( Red,

While taking Cephalexin for an alleged blood infection ( red, itchy skin lower legs while retaining fluid in his ankles) allowed to drink BEER while taking this medication.
This is my brother and he never listens, so I need a professional answer. I do understand some antibiotics are not allowed alcohol and some are allowed.
Thank you for any help you can give me for my brother