How I would treat essential meds would depend on how many & what size are required and how critical it is. A month's supply of my blood pressure pill will fit in a container the size of a 35mm film can. A week is smaller than a AAA flashlight. I keep a month back-up in rotation and about two weeks in pocket when traveling. I couldn't do this if it was bigger. For a river trip and a larger volume med, I'd be thinking something like a Pelican box that would stay attached to my PFD.