Field and Stream has good info on what medicines you should have with you when you go into the wilderness. If you go camping, hunting or backbacking you might want to read the article so that you will be better prepared when you go. I like the five they suggest and am adding a 6th suggestion to the list. I think you should also have a blood clotting agent in your bag in case you get a cut and are bleeding a lot.
http://www.fieldandstream.com/articles/hunting/2012/06/rx-wilderness-5-meds-you-need-stay-alive