They make a snakebite kit, and insect bite kit. You used to be able to get it at Walmart.
It is sort of a hypodermic syringe kind of a thing...you put it on there and suck out the venom.
I used to run in to a guy that was working on his thesis, or something or other. He would catch, tag and then release rattlers in Organ Pipe Cactus NM. He would then find the same snakes and catch them again and do whatever he did. He used to drive the highway and watch for them on the road.
He carried one. Once his hand didn't even swell up. The other time, he got it between the fingers. It was much worse. Keep in mind, that he was probably 30 minutes from the clinic and I don't expect that he fooled around once he got zapped.