help please

ok so my fiance got a tooth filled with a temporary, but 3 days ago it started hurting and his cheek started swelling up. yesterday he went to the hospital and they gave him penicillin, but that is only making it swell more he says (he is 100 miles from home at the moment, and just finally found a job that starts tomorrow). he can't go into his regular dentist, he has no insurance and no money at all (as in, all of his credit cards are over limit, his phone is shut down, and hasn't been able to make a single payment on his carecredit card that got him the temp in the first place broke). and it is one of his top incisors. (i'm a out of state college student that is missing $9000 of my fin aid for the year, so i can barely pay my own bills with the help of my parent)
my questions are these: why is the penicillin making it the swelling and pain worse? (and no he is not allergic to it) should he continue to take the penicillin? and is there a way of not pulling his tooth, given our financial bind?

[Jerome Tsang, DDS]

They can re-open it again and see whats going on.  It sounds like an abscess and would require a root canal in the long term.  The antibiotics may not be working.  It takes a few days for the antibiotics to work though so it may take some time.