Hello. My mother has been informed she has a kidney infection and been given cefalexin for treatment. She has a penicillin allergy and the DR s have said this is the only treatment available. I understand the hesitation my mother had about taking these but she s in some pain. Another complication is her Atrial Fibrillation and CFS/ME and any bout of sickness can kick off the AF. Any help is very much appreciated Thank you Ian