The most important step for people who use an indwelling catheter is to drink, drink, and drink some more. Your fluid intake should be enough so that your urine has the appearance of water or is only slightly yellow in color and clear. Changing your catheter after increasing your fluids may also help cut down on the number of bacteria living in your bladder since catheters can become "colonized" with the bacteria that are flushed out of your urinary tract. Generally, changing your catheter every month should be enough to keep you healthy, but people who get frequent UTIs or whose catheters tend to become encrusted with built-up mineral deposits may have to change it more often.
When you have completed your antibiotic prescription, it is not necessary to get a repeat culture unless your symptoms have not improved. Those who reuse their intermittent catheters find that recurrence of a UTI is less likely if they discard their current catheters and begin using new ones after treatment for a UTI.