Treatment of UTIs depends on the organism cultured, its sensitivities to antimicrobial agents and the severity of symptoms.
Some people with recurrent UTIs easily recognize their symptoms of dysuria (as described by our patient Mrs. Smith), urgency, flank pain, fever and/or chills.
If the patient has seen a health provider for a previous UTI and reports the same symptoms, the health provider may order an antimicrobial that has worked for that patient in the past without an office visit since certain people are prone to recurrent UTIs.
UTIs caused by bacteria require treatment with antibiotics. For those patients with uncomplicated cystitis, a 3-day course of trimethoprim-sulfamethoxazole or a fluoroquinolone usually eradicates potential bacterial pathogens in vaginal or gastrointestinal reservoirs. Single-dose therapy usually is not recommended because it results in higher recurrence rates. Mrs. Smith was given a longer course of treatment (7-14 days) because of her history of recurrent UTIs and diabetes. Patients with symptoms for more than a week should be given treatment of this duration.11
Asymptomatic bacteriuria, defined as bacteria in urine in a patient without urinary tract signs and symptoms, usually does not require treatment in the elderly, people with diabetes and those with indwelling urinary catheters because it may lead to the development of resistant bacteria that are more difficult to treat later if the patient becomes symptomatic. The exception to this is in pregnant women, although the antibiotic must be carefully chosen from oral beta-lactams, sulfonamides and nitrofurantoin, which are considered safe in early pregnancy. If the woman is in late pregnancy, sulfonamides should be avoided because they may be associated with kernicterus in the newborn.11
Treat acute pyelonephritis, an upper UTI, in a cooperative, immunocompetent outpatient without nausea, vomiting or septicemia with oral antibiotics. Typical regimens include a 14-day course of trimethoprim-sulfamethoxazole 160/800 mg by mouth twice a day or ciprofloxacin 500 mg by mouth twice a day.
Other patients with acute pyelonephritis should be hospitalized and given IV therapy based on the local sensitivities of the most commonly isolated strains until the patient's specific bacterial organism and sensitivities are known. Antibiotics include ampicillin plus gentamicin, trimethoprim-sulfamethoxazole with a fluoroquinolone, and broad-spectrum cephalosporins such as ceftriaxone.11
Treat complicated pyelonephritis, which is caused by obstruction, renal calculi, resistant or healthcare-associated bacteria, or recent urinary tract instrumentation, with aztreonam, a beta-lactam/beta-lactam inhibitor combination such as ampicillin/sulbactam, ticarcillin-clavulanate, piperacillin-tazobactam and imipenem-cilastatin.11 IV therapy should be continued until the patient clinically improves, including a decrease in temperature. In approximately 80 percent of patients, this occurs in 72 hours. At that point, the patient can be switched from IV antibiotics to oral ones and discharged to complete 14 days of therapy.
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Resistance to antibiotics continues to increase. About 25 percent of E. coli isolates and 33 percent of P. aeruginosa-causing CAUTI cases are resistant to the class of antibiotics called fluoroquinolones.10 Common fluoroquinolones include ciprofloxacin, levofloxacin and moxifloxacin.
Upset stomach, diarrhea and, in women, vaginal yeast infections are common side effects of antibiotics. Some side effects are more severe and, depending on the antibiotic, may impair the function of the kidneys, liver, bone marrow or other organs.
Colitis, an inflammation of the large intestine, may develop in some patients who take antibiotics.
This is especially true of cephalosporins, clindamycin or fluoroquinolones, and it's caused by a toxin produced by the bacteria Clostridium difficile, which is resistant to many antibiotics and grows unchecked in the intestines when antibiotics kill other normal bacteria in the bowel.12
If a urine culture grows a fungal organism but the patient has no signs or symptoms of a UTI, the patient does not need to be treated. Symptomatic UTIs caused by fungi require antifungals.
In addition, patients whose cultures grow fungi, including those who are immunocompromised, who have had a renal transplant or who are having urological manipulation, need antifungal treatment.
Prior to therapy, urinary catheters or stents should be removed if possible.
Two common therapies include oral fluconazole 200 mg once a day for 7-14 days, or IV amphotericin B. Amphotericin B also may be used for bladder irrigation. Relapse of fungal organisms is common, especially if a urinary catheter is left in place.13
Mrs. Smith's UTI was caused by E. coli, which was susceptible to TMP-SMX.
She was given 10 days of oral trimethoprim-sulfamethoxazole and has no further complaints of burning on urination.
Her UTI treatment was successful.
References for this article can be accessed here.
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Connie Cutler is the director of prevention and control for Main Line Health System, Wynnewood, PA.