i want to know what the side effects of mixing drugs are

if u mixed meth, klonopin, and solmas together what can it do to your body and your brain? how long do u have till this starts taking effect? Can you please tell me everything this might do to a person? long term effects, and short term effects. I know mixing these three together can cause saveire brain damage or liver falior, well sorry let me corect that, I dont know what doctors know but im really scared for my friends life he keeps mixing these drugs together and he wont listen to his mother and I when we tell him not to do that, mabe if it comes from a profetional he will listen a little better. Thanx for your time ho[e to hear from u soon sinserely Leanna