Question

Under what circumstances can cephalosporin be used in a patient who is allergic to penicillin?

Answer 1

If the hypersensitivity reaction was not Type I or severe Type II, III, IV, cephalosporins can be used in patients with a penicillin allergy. Cephalosporins may be safely prescribed for patients who have not had IgE-mediated (or other serious) reactions to penicillin. But before administering cephalosporin careful evaluation of the timing of the reaction, severity of reaction symptoms, and structural comparison of the penicillin that resulted in the allergy and the cephalosporin being analysed completely.

Both pencillins and cephalosporines have common betalactam ring. Cephalosporins are related to the structure and antimicrobial activity of penicillins. There is a common myth that  that about ten percentage of clients with a penicillin allergy history will experience an allergic reaction when administering cephalosporin.