Choose the antibiotics as per culture and sensitivity report. After episode over, investigate to find out cause of this UTI.. Ultrasound
KUB, Micturiting cystourethrograpm (to rule of vesico ureteric reflux), DMSA scan
to relu out renal scar.. If any structural abnormality detected , those abnormalities to be correcte , meanwhile, uroprophylaxis to be continued.
there is no wrong in going for strong medication until urine become sterile. If correct dosage as per body weight or surface area and correct route chosen, No problem with strong medication..