The risk of serious side effects means ciprofloxacin is generally not given to children in the U. Ciprofloxacin is often prescribed in cases in which bacteria have developed a resistance to amoxicillin or other antibiotics. While ciprofloxacin and amoxicillin can both have serious side effects, ciprofloxacin is generally considered the riskier of the two drugs and has received a black box warning from the U. Food and Drug Administration FDA because of the increased risk for ruptured tendons and more severe muscle weakness in patients with myasthenia gravis.
Amoxicillin is generally considered safe during pregnancy, but ciprofloxacin should be avoided by women during pregnancy and breastfeeding because of the risk of birth defects and other side effects. Both ciprofloxacin and amoxicillin can interact with other drugs, and patients should inform their doctors about any medications they are taking before beginning a regime of either of them. In general, amoxicillin is used as a first-line antibiotic, either by itself or in combination with other drugs, to treat a wide range of bacterial infections.
Adverse Events. Differences were due mostly to increased loose stools and vaginal symptoms in the women treated with amoxicillin-clavulanate. Twenty-two amoxicillin-clavulanate—treated women required treatment for adverse effects compared with 10 ciprofloxacin-treated women. Only 2 women in the amoxicillin-clavulanate group and 1 woman in the ciprofloxacin group discontinued study medication due to adverse effects. This is the first comparison of a 3-day regimen of amoxicillin-clavulanate vs a 3-day regimen of a fluoroquinolone for the treatment of acute uncomplicated cystitis in women.
Amoxicillin-clavulanate was markedly inferior to ciprofloxacin in clinical and microbiological cure rates as well as in eradication of vaginal E coli. Of concern, 2 women developed same-strain pyelonephritis soon after treatment with amoxicillin-clavulanate same-strain is presumed in 1 woman based on a urine culture 5 days before the episode of pyelonephritis. The difference in clinical cure occurred primarily within the first 2 weeks of treatment and was most likely due to the inferior activity of amoxicillin-clavulanate in eradicating E coli from the vagina.
In this regard, amoxicillin-clavulanate is similar to ampicillin and amoxicillin, drugs that also do not effectively eradicate E coli from the vaginal reservoir and are associated with high recurrence rates. Although not evaluated in this study, another factor that may have contributed to the poorer results seen with amoxicillin-clavulanate is the much shorter serum half-life of amoxicillin compared with ciprofloxacin 1. Although concerns have been raised about the effectiveness of amoxicillin-clavulanate in the treatment of UTIs caused by amoxicillin-resistant E coli , 10 we were unable to demonstrate that amoxicillin-resistant strains were associated with higher failure rates.
Finally, it has been demonstrated in an experimental mouse model that E coli , following inoculation of large quantities into the bladder, can penetrate into the bladder epithelium and produce intracellular colonies of bacteria and eventually biofilms.
The worldwide increase in trimethoprim-sulfamethoxazole resistance in E coli and concerns about fluoroquinolone resistance in UTIs and other more serious infections 3 highlight the need for alternative antibiotics for the treatment of cystitis. Nitrofurantoin and fosfomycin tromethamine have both been advocated as fluoroquinolone-sparing alternatives to trimethoprim-sulfamethoxazole, but neither appears to be as effective as trimethoprim-sulfamethoxazole or fluoroquinolones.
We chose to compare 3-day regimens of amoxicillin-clavulanate and ciprofloxacin for the treatment of acute uncomplicated cystitis because of the need for safe and effective fluoroquinolone-sparing antibiotics, the absence of a large trial comparing a 3-day regimen of amoxicillin-clavulanate to current standard therapy, and increasing amoxicillin-clavulanate use for the treatment of UTIs over the past decade.
In fact, amoxicillin-clavulanate was found to be significantly inferior to ciprofloxacin even in women infected with uropathogens susceptible in vitro to amoxicillin-clavulanate. Strengths of this study include its large sample size, well-defined study population, long follow-up period, low dropout rate, high rate of medication adherence, and genetic analysis of strains causing persistent and early recurrent UTIs. The single-blind study design is a potential weakness of the study if there was a clinical bias against amoxicillin-clavulanate and a subsequent lower threshold to treat women in this group who had mild symptoms.
This seems unlikely since the percentage of UTIs that were culture-confirmed and the percentage that were associated with pyuria were almost identical in the 2 treatment groups. Trimethoprim-sulfamethoxazole should continue to be the first-line treatment for acute cystitis if the woman has no history of allergy to the drug and if the likelihood of trimethoprim-sulfamethoxazole resistance is low.
Amoxicillin-clavulanate in a 3-day regimen is not as effective as a fluoroquinolone for the treatment of acute uncomplicated cystitis, even in those women with UTIs caused by susceptible uropathogens, and should be considered only when use of other first- and second-line antibiotics is not feasible. Corresponding Author: Thomas M. Author Contributions : Dr Hooton had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Critical revision of the manuscript for important intellectual content : Hooton, Scholes, Gupta, Stapleton, Roberts, Stamm. Stamm, principal investigator. Role of the Sponsor: Representatives of Bayer and Glaxo SmithKline had no input into the design or conduct of the study; in the collection, management, analysis, or interpretation of the data; or in the preparation, review, or approval of the manuscript.
No support was given by either company to conduct the study. Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy Continue.
Figure 1. Figure 2. Figure 3. Table 1. Table 2. Table 3. National patterns in the treatment of urinary tract infections in women by ambulatory care physicians.
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Hooton TM. One such antibiotic, amoxicillin-clavulanate, has not been well studied. Objective: To compare the efficacy of a 3-day regimen of amoxicillin-clavulanate to that of a 3-day regimen of ciprofloxacin in the treatment of acute cystitis in women. The primary study hypothesis was that the amoxicillin-clavulanate and ciprofloxacin treatment groups would differ in clinical cure.
Design, setting, and patients: Randomized, single-blind treatment trial of women, aged 18 to 45 years, with symptoms of acute uncomplicated cystitis and a urine culture with at least 10 2 colony-forming units of uropathogens per milliliter from a university student health center or a health maintenance organization.
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