Oral antibiotics can treat most bladder infections and uncomplicated kidney infections successfully. In many cases, if the symptoms and urinalysis suggest a urinary tract infection (UTI), you will start taking antibiotics without waiting for the results of a urine culture.

How long you will need to take antibiotics depends on the location of the infection, your age, your gender, and any complicating medical conditions.

• Women with uncomplicated bladder infections (cystitis) usually take antibiotics for 3 days. In the past, longer courses of treatment were common, but studies show that the shorter course of antibiotics is just as effective and causes fewer side effects.⁴
• Women with bladder infections who have had a recent UTI or who have symptoms for more than 7 days may require a 7-day course of antibiotics.
• Men with bladder infections usually take antibiotics for 7 to 14 days. If the prostate is infected as well, treatment may last 4 weeks or more.
• Men and women with kidney infections (pyelonephritis) may take antibiotics for 10 to 14 days. In severe cases, treatment may require intravenous (IV) antibiotics and fluids in a hospital.
• Men and women who are older than 65, have diabetes or an impaired immune system, or have other urinary problems usually require longer courses of antibiotics.
• People who have infections that do not respond to treatment or are complicated by other factors may require longer antibiotic therapy.

Antibiotics for recurrent infections

Doctors sometimes advise that women with repeat infections take antibiotics for 2 to 6 weeks, followed by preventive antibiotic therapy. This may include taking a small dose of antibiotics daily or on alternate days, taking antibiotics after sexual intercourse (since sex often triggers UTIs in women with recurrent infections), or taking antibiotics only when you develop symptoms. Talk with your doctor about which treatment strategy is appropriate for you.

Medication Choices

Antibiotic medications that treat UTIs include:

• Sulfonamides with trimethoprim (such as Bactrim or Septra).
• Trimethoprim (Proloprim).
• Fluoroquinolones (such as Cipro or Floxin).
• Cephalosporins (such as Keflex or Duricef).
• Nitrofurantoin (such as Macrobid or Macrodantin).
• Penicillins (such as ampicillin or amoxicillin).
• Tetracycline (such as Declomycin or Vibramycin).

Phenazopyridine treats the pain and burning that often accompany a UTI.

Be sure to tell your doctor if you are or think you may be pregnant. Some of these medications are not safe to use during pregnancy.

What To Think About

These medicines are often prescribed in a less costly generic form, rather than under a brand name. A pharmacist might also decide to give you a generic instead of a brand name medicine unless the prescription says "no generic."

Take all of the antibiotics your doctor has prescribed. Most people begin to feel better soon after they begin the medicine. But if you stop taking the medicine as soon as you feel better, the infection may return. More importantly, not taking the full course of antibiotics encourages the development of bacteria that are resistant to antibiotics. This not only makes antibiotics less effective but also makes bacterial infections more difficult to treat.