If bacteria is resistant to penicillin can you give erythromycin?
Yes, erythromycin is very similar to penicillin, in the types of
bacterial infections it can fight. Erythromycin is used in patients
who are allergic to penicillin, primarily. But an M.D. could
prescribe it to somebody who has developed a tolerance, or to an
infection that is penicillin- resistant. Typically, though, a
different antibiotic is chosen, given the similarities of the two
drugs.