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Published and unpublished randomised controlled trials were identified from the Cochrane Controlled Trials Register, MEDLINE, EMBASE, CINAHL, Current Contents, reference lists of review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 The manufacturers' of methenamine salts were contacted for unpublished studies and contact was made with known investigators in the area.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: In the era of multidrug resistance, it is critical to utilize antibiotics in an appropriate manner and to identify new treatments or revisit the use of 'forgotten' drugs. Because urinary tract infections (UTIs) are common, particularly in an increasing elderly population, the 'forgotten' drug, methenamine, may become important as a preventive therapy for recurrent UTIs. Methenamine, a urinary antibacterial agent, can be used as methenamine hippurate or methenamine mandelate preparations and is United States Food and Drug Administration-approved. This article discusses the place of preventive therapy for recurrent UTIs, chemistry, mechanism of action, pharmacology, clinical uses, dosage, adverse reactions and safety, and drug interactions of methenamine. Because of its unique antiseptic property, the authors suggest that methenamine should be considered when more commonly used antibiotics fail to suppress recurrent UTIs.Expert Review of Anticancer Therapy 04/2014; DOI:10.1586/14787210.2014.904202 · 3.22 Impact Factor
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ABSTRACT: Urinary tract infection is a common problem among patients with neurogenic bladder dysfunction that can be costly and challenging to manage. Current literature on the topic of preventing urinary tract infections in this heterogeneous patient population is challenged by the difficulty in defining urinary tract infections and by the lack of long-term data from controlled randomized studies. New research suggests that intradetrusor injection of onabotulinumtoxin A may be a useful adjunct in preventing urinary tract infections, and further studies are needed to determine if probiotics, bacterial interference, and/or vaccines will prove to be of use in the population.Current Bladder Dysfunction Reports 12/2014; 9(4). DOI:10.1007/s11884-014-0257-4
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ABSTRACT: INTRODUCTION AND HYPOTHESIS: Recurrent urinary tract infections (UTIs) are more common in women and are frequently defined as ≥2 episodes in the last 6 months or ≥3 episodes in the last 12 months. In a primary care setting, 53 % of women above the age of 55 years and 36 % of younger women report a recurrence within 1 year. Thus, management and prevention of recurrent UTI is of utmost significance. This review aims to highlight the latest research in prevention strategies and suggest a management pathway. METHODS: A search was conducted on MEDLINE, Embase and the Cochrane Database of Systematic Reviews databases for the latest systematic reviews and high-quality randomized controlled trials. Special emphasis was placed on the remit "recurrent" and strongly adhered to. Furthermore, a Google search was conducted for current guidelines on the management of UTIs. RESULTS: Current prevention strategies include eliminating risk factors that increase the risk of acquiring recurrent UTI and continuous, post-coital and self-initiated antimicrobial prophylaxis. Other prospective preventative strategies, currently under trial, include use of vaccinations, D-mannose and lactobacillus (probiotics). CONCLUSION: Although risk factors should be identified and addressed accordingly, individualized antibiotic prophylaxis remains the most effective method of management. Non-antibiotic prevention strategies such as cranberry, vitamin C and methenamine salts lack strong evidence to be introduced as routine management options and as alternatives to antibiotics. Based on current evidence and guidelines, a management pathway is recommended. Emerging therapies require further evaluation before they can be recommended.International Urogynecology Journal 10/2014; DOI:10.1007/s00192-014-2569-5 · 2.16 Impact Factor