It works the same way as an antibiotic. It's a part of the penicillin family and is primarily used to treat syphilis but doctors use it to treat other diseases and infections too.
This is from the website that makes Bicillin:
"BICILLIN® L-A can be used to treat infections due to penicillin-G-sensitive microorganisms susceptible to the low and very prolonged serum levels common to this dosage form. Therapy should be guided by bacteriological studies (including sensitivity tests) and by clinical response."
My previous LLMD had me on this for awhile. My wife had to give me the shots at home. Ouch! Seriously, it wasn't that bad but my butt got kinda sore from all the shots. I rotated them so that helped. : )
How's it going for you so far?