Urinary Tract Infection - Medications

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If fever and back pain persist after 72 hours of antibiotic administration, the doctor will usually order imaging tests to see if abscesses, obstructions, or other abnormalities are present.

Treating Chronic Kidney Infections. Patients with chronic pyelonephritis are often treated with long-term antibiotics, even during periods when they have no symptoms.

Treatments for Interstitial Cystitis

The two approved treatments for interstitial cystitis are pentosan polysulfate (Elmiron), and dimethyl sulfoxide (DMSO). Patients generally prefer Elmiron because it can be taken by mouth. A DMSO solution is instilled into the bladder through a catheter. Elmiron is a type of blood thinner that helps to coat the bladder lining and prevent infections. It may take several months before having an effect on symptoms, but the benefits increase the longer the drug is used.

Doctors sometimes also prescribe other types of medications to help interstitial cystitis symptoms. These drugs include antihistamines, such as hydroxyzine (Atarax), and low doses of the tricyclic antidepressant amitriptyline (Elavil). Drugs that reduce bladder spasms (hyoscine, oxybutynin) are also sometimes used. Other treatments are being investigated, including hyperbaric oxygen therapy. This treatment involves having a patient breathe pure oxygen inside a sealed pressurized chamber.

Some doctors think that interstitial cystitis may be related to immune disorders. Researchers are investigating various drugs that block immune and inflammatory responses.

Treatments for Specific Populations

Treating the Pregnant Woman. Pregnant women should be screened for UTIs, since they are at high risk for UTIs and their complications. The antibiotics used during pregnancy are amoxicillin, ampicillin, nitrofurantoin, or an oral cephalosporin. Fosfomycin (Monurol) is not as effective as others but may be used during pregnancy. Pregnant women should not take fluoroquinolones.

Pregnant women with even asymptomatic bacteriuria (evidence of infection but no symptoms) have a 30% risk for acute pyelonephritis in their second or third trimester. They need screening and treatment for this condition. In such cases, they should be treated with a short course of antibiotics (3 to 5 days). For an uncomplicated UTI, pregnant women may need longer-term antibiotics (7 to 10 days).

Treating Women with Diabetes. Women with diabetes have more frequent and more severe UTIs than women without the disease. Many experts recommend that patients with diabetes and UTI, even an uncomplicated infection, be treated with antibiotics for 7 to 14 days. People with diabetes have higher than average rates of asymptomatic bacteriuria, but it is unclear whether they should be screened and treated for this condition. A 2003 study indicated that treating this condition had little value in these women and did not prevent complications.

Treating Urethritis in Men. Urethritis in men has typically been treated with a 7-day regimen of doxycycline. Some research suggests that a single dose of azithromycin may be just as effective while causing fewer side effects. One-dose treatment also improves compliance, so cure rates may even be better than with a long-term regimen. However, once an infection spreads to the prostate gland it is harder to treat, so most doctors still prefer the longer regimen. Patients with urethritis should also be tested for an accompanying sexually transmitted disease such as gonorrhea.

Treating Children with UTIs. Children with UTIs are generally treated with TMP-SMX or cephalexin (Keflex). These drugs are usually taken by mouth in either liquid or pill form. Doctors sometimes give them as a shot or IV. Children usually respond to treatment within a few days. Antibiotic resistance to cephalosporin antibiotics such as cephalexin is increasing, and some doctors prefer to prescribe an aminoglycoside antibiotic. Gentamicin (Garamycin) is the aminoglycoside antibiotic that is most commonly used. It is given intravenously.

Vesicoureteral reflux (VUR) is a concern for children with UTIs. About a third of children with UTIs develop this condition, in which urine backs up into the kidneys. VUR can lead to kidney infection (pyelonephritis), which can cause kidney damage. Either long-term antibiotics or surgery are options to correct vesicoureteral reflux (VUR) and prevent infection. Many experts recommend surgery over antibiotics, especially due to concerns of antibiotic resistance. Antibiotic treatment usually continues for years with the idea that the condition will resolve when the child has grown. However, a 2006 study suggested that long-term antibiotics are not useful for preventing VUR. Furthermore, the study found that mild-to-moderate VUR does not increase the likelihood of UTIs or pyelonephritis.

Children with acute kidney infection are treated with oral cefixime (Suprax) or a short course (2 to 4 days) of an intravenous (IV) antibiotic (typically gentamicin, given in one daily dose). An oral antibiotic then follows the IV.

Review Date: 06/16/2006
Reviewed By: Harvey Simon, M.D., Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital