One year ago I had taken trimethoprim for Bacterial prostatitis for 3 months after that I stopped this medicine due to increase in serum creatinine 1.2 and protein in urine. after some days kidney function become normal. one year later Again I got Prostatitis and I taken trimethoprim for only 7 days and in these 7 days my serum creatinine continuously increased to 1.2 then now I have stopped it. why this happening with only 7 days of use. (Causeing bacteria e coli.) when should I take another antibiotic. should I wait for some days to start new antibiotic? (cefoperazone)