Assuming they were prescribed and not street drugs, the OP's brother was using muscle relaxer and anti-seizure and -anxiety meds. Considered together, that means that either the doctor was a mini Dr. Mengele, or the brother was a really messed up guy that the doctor was trying to bring under control. Since the brother was also using codeine and alcohol (how'd he get the codeine, G_55? It's not OTC!), that latter seems infinitely more likely to me.
G_55's brother screwed up his life, and the tools he used to screw it up finally killed him. Blaming the doctor who tried to help bring the guy back from the walking dead is pathetic and perverse. G_55 cannot seem to bring him/herself to admit that the brother was a victim of his own choices; G_55 needs the "victimizer" to be other than the brother.