If I had an allergic reaction to the z pack, what alternatives are there for me?

Drug Allergy. Z pack means Azithromycin which is a macrolide antibiotic. Clarithromycin (biaxin), Erythromycin are from the same group. So you can be allergic to these also. Your doctor need to know you are allergic to azithromycin. There are many other classes of alternative antibiotics. Your doctor will decide accordingly if you need antibiotic in the future.