Can any one suggest a powerful drug for a blister surrounded by armpit?

I need to buy the drug over the counter.Can any one suggest a powerful drug for a blister surrounded by armpit?
assumimg you got this as a "rub" from right to be heard your bra or t-shirt, it's most likely a boil (boil, blister, same difference right?). try this stuff call boil easy, it really help. you should be able to find it within the pharmacy section and if you can't only ask a pharmacist, that's why they're there! if that doesn't work or you can't find it, next just look for any medicated cream near benzocane (sp?) in it. and if worse comes to worse, lately dab some neosporin on it!
Okay, I sit here visualizing how one might capture a blister, Scaling ones self or maybe from a crutch?? Maybe a antibaterial cream? Sure it isn't an abcess??