March 17, 2008 — The American College of Obstetricians and Gynecologists (ACOG) has issued a practice bulletin to address the diagnosis, treatment, and prevention of uncomplicated acute bacterial cystitis and acute bacterial pyelonephritis in nonpregnant women. The new recommendations are published in the March issue of Obstetrics and Gynecology.
“An estimated 11% of U.S. women report at least one physician-diagnosed urinary tract infection (UTI) per year, and the lifetime probability that a woman will have a UTI is 60%,” write Jeanne Sheffield, MD, and colleagues from the ACOG Committee on Practice Bulletins. “Despite the frequency of UTIs, there is confusion about diagnostic strategies, and changes in antimicrobial resistance among uropathogens require alterations in traditional treatment regimens. The purpose of this bulletin is to address the diagnosis, treatment, and prevention of uncomplicated acute bacterial cystitis and acute bacterial pyelonephritis in nonpregnant women.”
These guidelines do not address management of complicated UTIs (eg, those occurring in patients with diabetes mellitus, abnormal anatomy, previous urologic surgery, a history of kidney stones, an indwelling urinary catheter, spinal cord injury, immunocompromise, or pregnancy).
Acute bacterial cystitis usually presents with dysuria, urinary frequency and urgency, sometimes with suprapubic pain or pressure, and rarely with hematuria or fever. The symptoms of acute urethritis from Neisseria gonorrhoeae or Chlamydia trachomatis infection, or genital herpes simplex virus type 1 and herpes simplex virus type 2, may be similar, and these conditions should be ruled out.
Upper UTI or acute pyelonephritis often presents with fever, chills, flank pain, and varying degrees of dysuria, urgency, and frequency.
Specific practice recommendations and their accompanying level of scientific evidence are as follows:
- In nonpregnant, premenopausal women, screening for and treatment of asymptomatic bacteriuria is not recommended (level of evidence, A).
- Antibiotic class should be changed when resistance rates are higher than 15% to 20% (level of evidence, A).
- Patients with acute pyelonephritis should complete 14 days of total antimicrobial therapy, regardless of whether treatment is on an inpatient or outpatient basis (level of evidence, A).
- For uncomplicated acute bacterial cystitis in women, including women 65 years and older, antibiotics should be administered for 3 days (level of evidence, A).
- Urine culture is not required for the initial treatment of a symptomatic lower UTI with pyuria or bacteriuria, or both (level of evidence, B).
- For the treatment of acute uncomplicated cystitis, beta-lactams, including first-generation cephalosporins and amoxicillin, are less effective than the preferred antimicrobials listed as treatment regimens (level of evidence, C).
- For the diagnosis of bacteriuria in symptomatic patients, decreasing the colony count to 1000 to 10,000 bacteria per milliliter will improve sensitivity without significantly reducing specificity (level of evidence, C).
A proposed performance measure is the percentage of women diagnosed with acute pyelonephritis who receive antimicrobial treatment for 14 days.
For uncomplicated acute bacterial cystitis, recommended treatment regimens are as follows:
- Trimethoprim–sulfamethoxazole: 1 tablet (160 mg trimethoprim–800 mg sulfamethoxazole) twice daily for 3 days. Adverse effects may include fever, rash, photosensitivity, neutropenia, thrombocytopenia, anorexia, nausea and vomiting, pruritus, headache, urticaria, Stevens-Johnson syndrome, and toxic epidermal necrosis.
- Trimethoprim 100 mg twice daily for 3 days. Adverse effects may include rash, pruritus, photosensitivity, exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrosis, and aseptic meningitis.
- Ciprofloxacin 250 mg twice daily for 3 days, levofloxacin 250 mg once daily for 3 days, norfloxacin 400 mg twice daily for 3 days, or gatifloxacin 200 mg, once daily for 3 days. Adverse effects may include rash, confusion, seizures, restlessness, headache, severe hypersensitivity, hypoglycemia, hyperglycemia, and Achilles tendon rupture (in patients older than 60 years).
- Nitrofurantoin macrocrystals 50 to 100 mg 4 times daily for 7 days, or nitrofurantoin monohydrate 100 mg twice daily for 7 days. Adverse effects may include anorexia, nausea, vomiting, hypersensitivity, peripheral neuropathy, hepatitis, hemolytic anemia, and pulmonary reactions.
- Fosfomycin tromethamine, 3-g dose (powder) single dose. Adverse effects may include diarrhea, nausea, vomiting, rash, and hypersensitivity.
“A 3-day antimicrobial regimen is now the recommended treatment for uncomplicated acute bacterial cystitis in women, with bacterial eradication rates consistently higher than 90%,” the authors of the recommendations write. “Use of trimethoprim–sulfamethoxazole for 3 days is considered the preferred therapy, with a 94% bacterial eradication rate. However, in areas where resistance to this antimicrobial agent exceeds 15-20%, another one of the listed regimens should be chosen.”
For women with frequent recurrences of lower UTI, continuous prophylaxis has been shown to decrease the risk for recurrence by 95%. Suitable prophylactic regimens include once-daily treatment with nitrofurantoin, norfloxacin, ciprofloxacin, trimethoprim, trimethoprim–sulfamethoxazole, or another agent listed in this article. The need for continued therapy can be re-evaluated after 6 to 12 months.
Although acute pyelonephritis traditionally has been treated with hospitalization and parenteral antibiotics, cost-savings measures have prompted a recent shift to outpatient management, whenever feasible.
“Imaging of the urinary tract rarely is required in women — it is not cost-effective nor does it provide useful information in the setting of uncomplicated lower or upper UTIs,” the authors conclude. “Women with infections that do not respond to appropriate antimicrobial therapy or in whom the clinical status worsens require further evaluation. Renal ultrasonography is the best noninvasive method to evaluate renal collecting system obstruction, [and] an intravenous pyelography also may be useful in this situation.”
Obstet Gynecol. 2008;111:785-794.