I had no side effects at all. I think if you are not allergic to penicillin you would be alright. But I would have a nurse do the first injection just in case. Maybe call your doctor's office and see if they are willing. Mine was but my husband ended up doing them. Unfortunately they didn't help me at all. I had the most success with Rocephin and am now on my second round of IV but it doesn't seem to be doing anything this time around.
I know people have had good luck with the Bicillin but in order to be effective they have to be given 3X weekly according to my doctor (Dr. H). I started on two and quickly went to three. I was on them almost 4 months with no improvement but I had to give it a try. I wish you luck with them and if you have any other questions I will be happy to answer them.