The wrong outlet

I have a friend who had severe migraines for all of his life. Recently it was so bad that he got hospitalized and it was just a mess. He had taken percocets and vicodin and some tylenol with codeine to fend off the pain but this time it was really bad and he told his doctor that the pain was just becoming too much to handle. His doctor prescribed him oxycodone. I understand that this is a pretty strong drug sometimes given to cancer patients in intensly severe pain. He started taking this "oxy" and it seemed to be working to get rid of his migraine (or atleast shield it). But then his tolerance grew after many experiences with the oxy. He thought that this was his only outlet to his severe pain and began taking more and more for the pain. Ultimately he overdosed and was put in the hospital when found laying on the floor unconcious. After this incident he kept having his migraines and really almost thought nothing of his overdose. He kept taking the oxy and only a month ago to the date he overdosed and died. He was a good friend and it really pains me to see him losing his life to a doc prescribed drug. What can be done to stop this overuse of meds? Why are so many kids experimenting with drugs? What could have been done for my friend.

PLEASE SHARE ANY EXPERIENCES WITH PRESCRIPTION MEDS I WANT SOME ANSWERS