I assume you know about the pubmed journal index? I used to use it a lot a medical school, it's a lot easier to use now it's on the web. Do a few searches on Home - PubMed - NCBI and see what journal articles come up - the cutting edge stuff is published in the journals way before it reaches text books.

On your orignal idea about antivenin in an epipen... biggest problem is preventing the protein from denaturing, most proteins (I believe all snake venoms are proteins, maybe a few enzymes as well) will breakdown when heated, and ambient temperatures over a short time would most likely be enough to denature the antivenin.
I'm happy to be wrong, but I think there's a reason why we don't have antivenin stored at room temp. Let us know what you find.