Study Evaluates Antibiotic Option for Treating Bladder Infection in Women
Short-term use of the antibiotic cefpodoxime for the treatment of women with uncomplicated cystitis (bladder infection) did not meet criteria for noninferiority for achieving clinical cure compared with ciprofloxacin, a drug in the fluoroquinolone class of antibiotics for which there have been concerns about overuse and a resulting increase in resistance rates, according to a study in the February 8 issue of JAMA. The criteria for noninferiority was if the efficacy of cefpodoxime had been shown to be within a pre-specified margin of 10 percent of the efficacy of ciprofloxacin.
Fluoroquinolones have high rates of efficacy and minimal adverse drug reactions when used in a 3-day regimen as recommended to treat uncomplicated cystitis. However, increasing rates of antimicrobial resistance among fluoroquinolones have been reported. To prevent further emergence of fluoroquinolone resistance, there are calls for restricting fluoroquinolones to those specific instances of uncomplicated cystitis when other first-line urinary tract infection (UTI) antimicrobials are not suitable, according to background information in the article. “Cefpodoxime, with its broad spectrum of antimicrobial activity, would provide a useful alternative to fluoroquinolones for the treatment of cystitis if demonstrated to be similar in efficacy to fluoroquinolones and without adverse ecological effects (such as the selection of drug-resistant organisms).”
Thomas M. Hooton, M.D., of the University of Miami, and colleagues conducted a clinical trial to assess whether cefpodoxime would have clinically acceptable efficacy and tolerance compared with ciprofloxacin.
The study, conducted from 2005 to 2009, included 300 women ages 18 to 55 years with acute uncomplicated cystitis. Outcomes were assessed at 5 to 9 days and 28 to 30 days after completion of therapy. Intent-to-treat and per-protocol analyses were performed; 15 women in the ciprofloxacin group (n = 150) and 17 women in the cefpodoxime group (n = 150) were lost to follow-up. Patients were randomized to 250 mg of ciprofloxacin orally twice daily for 3 days or 100 mg of cefpodoxime proxetil orally twice daily for 3 days. Overall clinical cure was defined as not requiring antimicrobial treatment during follow-up through the 30-day follow-up visit. The hypothesis that cefpodoxime would be noninferior to ciprofloxacin by a 10 percent margin was formulated prior to data collection.
The researchers found that the overall clinical cure rate with the intent-to-treat approach in which patients lost to follow-up were attributed as having clinical cure was 93 percent (139/150) for ciprofloxacin compared with 82 percent (123/150) for cefpodoxime. The test of noninferiority was not statistically significant. In an alternative intent-to-treat analysis in which patients who were lost to follow-up were considered to have not responded to treatment, the clinical cure rate was 83 percent (124/150) for ciprofloxacin compared with 71 percent (106/150) for cefpodoxime. Among women who reported no previous UTI in the past year before enrollment, the overall clinical cure rate was 96 percent for ciprofloxacin and 83 percent for cefpodoxime, a magnitude of difference that was not seen among women who reported 1 or more UTIs in the past year before enrollment.
Bladder infections are known as cystitis or inflammation of the bladder. They are common in women but very rare in men. About 20% of all women get at least one bladder infection at some time in their lives. However, a man’s chance of getting cystitis increases as he ages due to in part to an increase in prostate size.
Doctors aren’t sure exactly why women have many more bladder infections than men. They suspect it may be because women have a shorter urethra, the tube that carries urine out of the bladder. This relatively short passageway - only about an inch and a half long - makes it easier for bacteria to find their way into the bladder. Also, the opening to a woman’s urethra lies close to both the vagina and the anus. That makes it easier for bacteria from those areas to get into the urinary tract.
Bladder infections are not serious if treated right away. But they tend to come back in some people. Rarely, this can lead to kidney infections, which are more serious and may result in permanent kidney damage. So it’s very important to treat the underlying causes of a bladder infection and to take preventive steps to keep them from coming back.
In elderly people, bladder infections are often difficult to diagnose. The symptoms are less specific and are frequently blamed on aging. Older people who suddenly become incontinent or who begin acting lethargic or confused should be checked by a doctor for a bladder infection.
The clinical cure rate at the first follow-up visit (average, 5 days after treatment) was 93 percent for ciprofloxacin compared with 88 percent for cefpodoxime. The microbiological cure rate at the first follow-up visit (average, 5 days after treatment) was 96 percent for ciprofloxacin compared with 81 percent for cefpodoxime. At first follow-up, 16 percent of women in the ciprofloxacin group compared with 40 percent of women in the cefpodoxime group had vaginal E coli colonization (the presence of organisms on some surface or in some bodily fluid that are not causing symptoms). The differential effect of the two drugs on vaginal E coli colonization may have played a role in the difference in clinical outcomes.
Signs and Symptoms:
Pain or burning during urination
The need to urinate more often than usual
A feeling of urgency during urination
Blood or pus in the urine
Cramps or pain in the lower abdomen
Chills or fever (fever may be the only symptom in infants and children)
Strong smelling urine
Pain during sexual intercourse
Nausea, vomiting, and malaise
What Causes It?:
Risk factors include:
A new sex partner or multiple partners
More frequent or intense intercourse
Diabetes
Pregnancy
Escherichia coli (E. coli)
Staphylococcus saprophyticus
Use of irritating products, such as harsh skin cleansers
Use of irritating contraceptives, such as diaphragms and spermicides
Use of birth control pills
Heavy use of antibiotics
A blockage in the urinary tract (benign masses or tumors)
A history of UTIs, especially if the infections were less than 6 months apart
“Among women with uncomplicated cystitis, a 3-day regimen of cefpodoxime compared with ciprofloxacin did not meet criteria for noninferiority for achieving clinical cure,” the authors write. They add that this finding, along with concerns about possible ecological adverse effects associated with other broad-spectrum β-lactams (a class of antimicrobials that includes cefpodoxime), do not support the use of cefpodoxime as a first-line fluoroquinolone-sparing antimicrobial for acute uncomplicated cystitis.
###
(JAMA. 2012;307[6]:583-589. Available pre-embargo to the media at http://www.jamamedia.org)
Editor’s Note: This work was supported by grants from the National Institute of Diabetes and Digestive and Kidney Diseases. The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr. Hooton reported that he has been a consultant for Pinnacle Pharmaceuticals, Pfizer Inc., and Alita Pharmaceuticals. No other author reported disclosures.
###
Source: American Medical Association (AMA)