If you can take the "cillins", just go to a pet supply store and get fish mox or fish cillin used for tank treatment. It's the exact same 250MG tablets you will get from a prescription at a pharmacy...Amoxicillin or Ampicillin. I get mine from
www.foster&smith.com pet supply. About $20 for 100 tabs of Amox., a bit more for Ampi.