Chest pains related to vicodin addiction?

I'm really not too sure about anything concerning vicodin. However I know it can be very addictive and I have a friend who takes probably 6 a day. For about the past year i have heard him complain about chest pains off and on.. the last few months have been really bad though. He gets these terrible chest pains and he can't really breathe, his face turns red and he always just hunches over. He is only 19 years old so I am positive this is not normal. Whenever I try to talk to hm about his addicition or his pain, he freaks out. Are these pains somehow related to the vicodin?? If anybody has gone through this or knows anything about it let me know please..