When initiating treatment, rapid hydration of the patient can increase urine production and facilitate clearance of some bacteria through voiding. As discussed earlier, urinary pH plays an integral role in the innate antibacterial activity of urine. Ingestion of cranberry juice (in large quantities) can acidify the urine because cranberries contain precursors of hippuric acid, a weak organic acid. Hence, urine becomes a less hospitable medium for bacterial overgrowth, helping prevent both extension of current infection and future bacterial overgrowth.

In complicated infections, the duration and choice of therapy depend on the population in question.