You need to look up the medicine on the web and you can also call your local pharmacy to ask them for information/advice.
If you know the manufacturer of the medicine, they will be glad to answer any or all of your questions about the medicine. They are always a wealth of information and they obviously know all the info about what you are asking.
Good luck but for now I would say he should not at all be using alcohol with the meds he is on! Could be life theatening!