Hello, Thanks for writing to HealthCareMagic, I am Dr Muhammd Ahmad, I have closely read your question and I understand your concerns, I will hereby guide you regarding your health related problem. It shows that your brother had allergy to above mentioned medicines, doctor changed group of medicine but still your brother showed allergy it means the drugs has to be changed again so that a group of meds can be found which is effective but doesn t cause allergy. In this regard it s better to get a urine culture to know which infection is there plus get an allergy tests of meds which are shown to be sensitive in culture sensitivity testing ...this will help your doctor to chose a better antibiotic which is more effevtive and doesnt cause allergy. I hope this answered your question, if you have more feel free to ask,otherwise close the discussion and rate it. Regards. Dr.Muhammad Ahmad. General and Family Physician..