If I'm allergic to keflex antibiotics am I allergic to penicillin?
I was put on Keflex antibiotics and found out that I was severly allergic to it, does that mean I'm allergic to penicillin or any other drugs?
Keflex (or Cephalexin) is a 1st Generation Cephalosporin. Just as Wannam mentioned, they are Beta-Lactam drugs that inhibit cell wall synthesis, but they are less susceptible to penicillinases.
There is a 5-30% chance that you can have a cross-sensitivity.