Can I take Cephalexin if allergic to Penicillin?

23 Jun 2004

Dear Annarossana,

That's not an easy question to answer.
Some people are allergic to penicillins and can be given cephalosporins since the molecular structure of these 2 groups of medicines is different.

However, there are persons with multiple allergies who develop allergies to several types of medication.

In your case, the tentative answer is yes, you may. However, it is suggested that you watch yourself while taking the medication. If you start having itches, rashes or any form of discomfort especially difficulty of breathing, stop taking the medication at once and consult your doctor.

Best regards.

elephas888

1 Apr 2012

No! Do not take any drug containing cephalosporins if you are allergic to penicillin. This drug is a "cousin" let's say, to penicillin. In my case it causes a severe reaction, and I was hospitalized for 5 days by taking a drug named Vantin... a ceph antibiotic. We do better with sulfa drugs & erythromycin.