What is best drug for cystitis if mild renal damage?

Based on urine cx's. Usually the treatment is based on what the urine culture shows (e.g. What bacteria in the urine is causing the cystitis). Dosages of antibiobitics that can affect renal function will need to be adjusted for degree of kidney insufficiency. However, most of the antibiotics used to treat bacterial cystitis do not have to be adjusted for mild renal damage.