For people allergic to Penicillin or Amoxicillin, doctors usually prescribe other antibiotics such as Cephalexin, Clindamycin, or Azithromycin, depending on the severity of the allergy and the patient’s age. When discussing alternatives with the doctor, it’s helpful to ask about effectiveness against strep bacteria, possible side effects, proper dosage, and the length of the treatment course. You might also ask if there are any foods or medications to avoid while taking the alternative antibiotic, and how quickly you can expect symptom improvement.