Methenamine hippurate for preventing urinary tract infections.
ABSTRACT Methenamine salts are often used for the prevention of urinary tract infection (UTI).
To assess the effectiveness of methenamine hippurate in preventing UTI.
Published and unpublished randomised controlled trials were identified from the Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, Current Contents, reference lists of review articles and retrieved trials. The manufacturers' of methenamine salts were contacted for unpublished studies and contact was made with known investigators in the area.
Randomised and quasi-randomised trials of methenamine hippurate used for the prevention of UTIs in all population groups were eligible for inclusion. A comparison with a control (no treatment) group was a prerequisite to selection.
Two reviewers (BL and TB) performed independent assessment and data extraction using a standardised format. Discrepancies, methodological and interpretative issues were discussed with JS or JC. An exploration of heterogeneity as well as a detailed description of results grouped by population was conducted.
Eleven studies met the inclusion criteria. All trials were included in a descriptive analysis. Seven trials were included in meta-analyses. Four trials (199 patients) studied symptomatic bacteriuria and six trials (341 patients) studied bacteriuria as an outcome measure. Overall, trial quality was poor. The direction of six of the pooled trials was towards a favourable treatment effect from methenamine hippurate. Interpretation of the pooled estimates was not done in view of underlying heterogeneity. The study by Pettersson 1989 explained some, but not all, of the underlying heterogeneity. This study differed from all others by including patients with known upper renal tract abnormalities. Adverse reactions were mentioned by 10 studies. The rate of adverse events was low.
There is not enough evidence to conclusively support the use of methenamine hippurate for urinary prophylaxis. An exploration of heterogeneity raises the (hypothesis generating) possibility that methenamine hippurate may have some efficacy in patients without but not in patients with known upper renal tract abnormality (with asymptomatic bacteriuria as the outcome measure). Due to the small sample size and methodological problems within the studies involved, interpretation of these data should be done cautiously. The rate of adverse events reported by the trials was low, which suggests that current usage is unlikely to be causing significant harm.
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ABSTRACT: Urinary tract infections (UTIs) are symptomatic infections of the urinary tract, mainly caused by the bacterium Escherichia coli. One in two women suffers from a UTI at least once in her life. The young and sexually active are particulaly affected, but it is also seen in elderly, postmenopausal women. The likelihood of recurrence is high. Diagnosis is made with regard to typical complaints and the presence of leucocytes and nitrites in the urine. A culture is unnecessary in most cases. Uncomplicated UTI should be distinguished from complicated UTI, which has a risk of severe illness. The treatment of choice--short-term therapy with trimethoprim or nitrofurantoin--is successful in over 80% of the cases. Co-trimoxazol fluoroquinolones or cephalsporins are not considered first-choice drugs. There are indications that general practitioners' (GPs') management of UTI is not always optimal, specifically concerning diagnostic tests, the application of second-choice antibiotics, and the length of prescribed treatment courses. Many points relevant to GPs requirefurther research, such as epidemiology and resistance of urinary pathogens in the community and natural history of UTI, as well as optimal management in elderly or complicated patients and men.British Journal of General Practice 10/2002; 52(482):752-61. · 2.36 Impact Factor
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ABSTRACT: Recurrent urinary tract infections are caused by a combination of host factors and bacterial virulence. The patient with symptoms suggestive of recurrent urinary tract infections benefits from cultures to confirm the diagnosis of recurrent infections. The community also benefits because they allow for the tracking of resistant patterns. Once a patient has been diagnosed with recurrent urinary tract infections, there are a number of treatment choices in terms of initial treatment and prophylaxis. Treatment of the acute infection should follow the published guidelines of the Infectious Diseases Society of America taking into account local patterns of resistance. Younger patients can prevent infections by avoiding spermicides and taking cranberry tablets. Older patients may prevent infections by using estrogen and emptying their bladders fully. All patients may benefit from using antibiotic prophylaxis.Current Urology Reports 11/2003; 4(5):399-403. DOI:10.1007/s11934-003-0015-1 · 1.51 Impact Factor