Dave,
Do you prefer the gray or the black duct tape? I have found the black seems to have more practical uses, but I know some people are so traditional.....
No, really, I agree wholeheartedly with the idea of duct tape. Great stuff.
Actually, if you are really going backcountry, I don't think it is a bad idea to have an Epipen (adrenalin) along. It requires a prescription, and a knowledgable user, but it is really a potential lifesaver.
Benedryl is a great drug to have, and I have found a handful of decongestants like Sudafed to be quite helpful to have along, say, on a multiday river trip.
I have found that a bottle of Adolf's Meat Tenderizer (papain) is a helpful thing to have for bee or wasp stings. It is a digestive enzyme that breaks down the venom if made into a paste and applied to the skin immediately after a sting. Often avoids the need for the other stuff mentioned above if you can get to it quick. I've used it often with great success.