Effect of methenamine hippurate shortage on antibiotic prescribing for urinary tract infections in Norway-an interrupted time series analysis.

BACKGROUND: Despite a lack of conclusive evidence of effect, methenamine hippurate is widely prescribed as preventive treatment for recurrent urinary tract infections (UTIs) in Norway. A national discontinuation of methenamine hippurate treatment due to a 4-month drug shortage in 2019 presented an opportunity to evaluate its preventive effect on UTIs among regular users. OBJECTIVE: To estimate the impact of the methenamine hippurate drug shortage on prescription frequency of UTI antibiotics. METHODS: Data from The Norwegian Prescription Database was analysed using an interrupted time series design. The time series consisted of 56 time periods of 14 days. The model included two naturally occurring interruptions: (i) the methenamine hippurate drug shortage, and (ii) reintroduction of the drug. The study population were 18 345 women ≥50 years receiving ≥2 prescriptions of methenamine hippurate in the study period before the shortage. Main outcome measure was number of prescriptions of UTI antibiotics per 1000 methenamine hippurate users. Prescription rates of antibiotics for respiratory tract infections were analysed to assess external events affecting antibiotic prescribing patterns. RESULTS: We found a significant increase of 2.41 prescriptions per 1000 methenamine hippurate users per 14-day period during the drug shortage (95%CI 1.39, 3.43, P < 0.001), followed by a significant reduction of -2.64 prescriptions after reintroduction (95%CI -3.66, -1.63, P < 0.001). CONCLUSIONS: During the methenamine hippurate drug shortage, we found a significant increase in prescribing trend for UTI antibiotics followed by a significant decrease in prescribing trend after reintroduction. This change in trend seems to reflect a preventive effect of the drug on recurrent UTIs.

The resurgence of methenamine hippurate in the prevention of recurrent UTIs in women- a systematic review.

PURPOSE OF REVIEW: Recurrent urinary tract infections (rUTIs) in women are prevalent and difficult to manage. The rise of antimicrobial resistance makes it prudent to re-investigate the role of nonantimicrobial agents in the prevention of RUTIs. We wanted to evaluate randomised controlled trials (RCTs) that employed methenamine hippurate as a therapy or prophylactic in adult women with rUTIs. RECENT FINDINGS: Relevant databases were searched for RCTs using Cochrane methodology and reporting items for systematic reviews and meta-analyses (PRISMA) checklist, comparing the efficacy of methenamine hippurate to either an antibiotic or a placebo for the prophylaxis of rUTI in women.Six trials involving 322 patients taking methenamine and 419 patients receiving antibiotics in total were evaluated. The duration of the trials ranged from 12-24 months. Studies reported that methenamine was effective in extending the mean period between symptomatic episodes of urinary tract infections (UTIs), keeping the patient symptom- and infection-free, and reducing the number of UTI episodes. The newer studies reported that methenamine reduced the incidence rates of recurrent UTIs and was not inferior to the antibiotic in this regard. SUMMARY: The outcomes of methenamine hippurate were found to be at par with the antibiotic prophylaxis. It might serve as a suitable alternative nonantibiotic prophylaxis for females with rUTIs.

Methenamine hippurate compared with trimethoprim for the prevention of recurrent urinary tract infections: a randomized clinical trial.

INTRODUCTION AND HYPOTHESIS: The objective was to find an alternative treatment to a low-dose antibiotic for the prevention of recurrent urinary tract infections (UTI) and to evaluate the difference in rates of reinfection within 1 year when treated with methenamine hippurate for prophylaxis compared with trimethoprim. METHODS: We present a non-blinded randomized trial comparing methenamine hippurate with trimethoprim for the prevention of recurrent UTI at 12 months after starting treatment. Women over 18 who had at least two culture-positive UTI in the prior 6 months or three in the prior year were included. Ninety-two patients met enrollment criteria and were randomized to receive daily prophylaxis with methenamine hippurate or trimethoprim for a minimum of 6 months. Both intent-to-treat and per-protocol analyses if patients received the alternative drug after randomization were analyzed using Student's t test, Mann-Whitney U test, Kaplan-Meier curves, log-rank test, and a logistic and multivariate regression model. The primary outcome of this study was culture-proven UTI recurrence by 12 months after initiating prophylaxis. RESULTS: In the intent-to-treat analysis, we found no difference between groups in recurrent UTI, with a 65% (28 out of 43) recurrence in the trimethoprim group versus 65% (28 out of 43) in the methenamine hippurate group (p = 1.00). In the per-protocol analysis, 65% (26 out of 40) versus 65% (30 out of 46) of patients had UTI recurrences in the trimethoprim group versus the methenamine hippurate group (p = 0.98). CONCLUSIONS: Methenamine hippurate may be an alternative for the prevention of recurrent UTI, with similar rates of recurrence and adverse effects to trimethoprim.

Should I stay or should I go? A qualitative study exploring participation in a urology clinical trial.

INTRODUCTION AND HYPOTHESIS: The aim of this study was to identify modifiable factors to improve recruitment in a urology clinical trial of women with recurrent urinary tract infection (rUTI). An embedded qualitative study was conducted with patients and recruiting clinicians in the first 8 months of the trial. We present a matrix of factors influencing how patients make decisions about trial participation. METHODS: This was a qualitative study using telephone interviews. When they were first approached about the trial, women were asked to complete an expression of interest form if they wished to be contacted for an interview. Data were analysed thematically. NVivo 10 software (Qualitative data analysis software. 10th ed: QSR International Pty Ltd; 2012) was used as a management tool. RESULTS: Thirty patients and 11 clinicians were interviewed. Influences on patient participation included the impact of rUTI on quality of life (QoL), understanding of antibiotic resistance, and previous experiences with antibiotics either positive or negative. Very few women who declined the trial agreed to be interviewed. However, some of those who participated had reservations about it. These included the perceived risk of trying a new treatment, trial length, and the burden of participating. One person interviewed left the trial because of repeated infections and difficulties getting general practitioner appointments. CONCLUSIONS: A combination of factors worked to influence women to decide to participate, to remain in, or to leave the trial. A better understanding of how these factors interact and work can assist in the recruitment and retention of individual trial participants.

Lower urinary tract infections in women.

In her lifetime, a woman is highly likely to develop at least one lower urinary tract infection. Early detection and treatment are key. Being aware of predisposing factors for infection and understanding appropriate diagnosis and treatment regimens will help nurses in both primary and acute care manage these patients correctly. This will not only benefit patients but will also help prevent incorrect antimicrobial management and avoid unplanned admissions. This aim of this article is to provide nurses with the information they need to best advise both colleagues and patients on how to manage lower urinary tract infections in women.

Methenamine hippurate for preventing urinary tract infections.

BACKGROUND: Methenamine salts are often used as an alternative to antibiotics for the prevention of urinary tract infection (UTI). This review was first published in Issue 1, 2002 and updated in Issue 4, 2007. OBJECTIVES: To assess the benefits and harms of methenamine hippurate in preventing UTI. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library), MEDLINE (from 1950), EMBASE (from 1980), reference lists of articles and abstracts from conference proceedings without language restriction. Manufacturers' of methenamine salts were contacted for unpublished studies and contact was made with known investigators.Date of last search: June 2012 SELECTION CRITERIA: Randomised controlled trials (RCT) and quasi-RCTs of methenamine hippurate used for the prevention of UTIs in all population groups were eligible. A comparison with a control/no treatment group was a prerequisite for selection. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as risk ratio (RR) for dichotomous outcomes with 95% confidence intervals (CI). An exploration of heterogeneity and a detailed description of results, grouped by population, was undertaken. MAIN RESULTS: Thirteen studies (2032 participants) were included. Six studies (654 patients) reported symptomatic UTI and eight studies (796 patients) reported bacteriuria. Overall, study quality was mixed. The overall pooled estimates for the major outcome measures were not interpretable because of underlying heterogeneity. Subgroup analyses suggested that methenamine hippurate may have some benefit in patients without renal tract abnormalities (symptomatic UTI: RR 0.24, 95% CI 0.07 to 0.89; bacteriuria: RR 0.56, 95% CI 0.37 to 0.83), but not in patients with known renal tract abnormalities (symptomatic UTI: RR 1.54, 95% CI 0.38 to 6.20; bacteriuria: RR 1.29, 95% CI 0.54 to 3.07). For short-term treatment duration (1 week or less) there was a significant reduction in symptomatic UTI in those without renal tract abnormalities (RR 0.14, 95% CI 0.05 to 0.38). The rate of adverse events was low. AUTHORS' CONCLUSIONS: Methenamine hippurate may be effective for preventing UTI in patients without renal tract abnormalities, particularly when used for short-term prophylaxis. It does not appear to work in patients with neuropathic bladder or in patients who have renal tract abnormalities. The rate of adverse events was low, but poorly described.There is a need for further large well-conducted RCTs to clarify this question, particularly for longer term use for people without neuropathic bladder.

Methenamine for Recurrent Urinary Tract Infections in Solid Organ Transplantation.

INTRODUCTION: Recurrent urinary tract infections remain a challenge in solid organ transplant and have a negative impact on morbidity/mortality. PROJECT AIM: The purpose of this program evaluation was to determine the impact of methenamine on recurrent urinary tract infection in kidney and liver-kidney transplant recipients. DESIGN: This retrospective review included patients > 18 years of age who received a kidney or liver-kidney transplant. Patients were divided into the following groups: (1) Methenamine therapy initiation received methenamine for ≥ 180 days or (2) Non-methenamine therapy: did not receive recurrent urinary tract infection prophylaxis. A total of 60 patients were included. RESULTS: When comparing outcomes between methenamine therapy initiation and non-methenamine therapy group, a significant reduction in the rate of recurrent urinary tract infection was reported in the methenamine therapy initiation group (0.6 vs 1.3 per 180 patient days follow-up, P = 0.0005). A significant reduction was also noted with rate of asymptomatic bacteriuria, treatment failures, bacteremia, hospitalizations due to recurrent urinary tract infection, multi-drug resistant organism isolated, and the average duration of antibiotic use. A significant difference in the time to failure of methenamine therapy initiation versus non-methenamine therapy is noted up to 180 patient-days follow-up (RR 1.56, P = 0.0019). CONCLUSION: This evaluation supported methenamine therapy for recurrent urinary tract infection in kidney and liver-kidney transplant. The most significant impact of methenamine recurrent urinary tract infection was seen in the first 30 days after initiation.

GPR109A mediates the effects of hippuric acid on regulating osteoclastogenesis and bone resorption in mice.

The G protein-coupled receptor 109 A (GPR109A) is robustly expressed in osteoclastic precursor macrophages. Previous studies suggested that GPR109A mediates effects of diet-derived phenolic acids such as hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA) on promoting bone formation. However, the role of GPR109A in metabolic bone homeostasis and osteoclast differentiation has not been investigated. Using densitometric, bone histologic and molecular signaling analytic methods, we uncovered that bone mass and strength were significantly higher in tibia and spine of standard rodent diet weaned 4-week-old and 6-month-old GPR109A gene deletion (GPR109A-/-) mice, compared to their wild type controls. Osteoclast numbers in bone and in ex vivo bone marrow cell cultures were significantly decreased in GPR109A-/- mice compared to wild type controls. In accordance with these data, CTX-1 in bone marrow plasma and gene expression of bone resorption markers (TNFα, TRAP, Cathepsin K) were significantly decreased in GPR109A-/- mice, while on the other hand, P1NP was increased in serum from both male and female GPR109A-/- mice compared to their respective controls. GPR109A deletion led to suppressed Wnt/ß-catenin signaling in osteoclast precursors to inhibit osteoclast differentiation and activity. Indeed, HA and 3-3-PPA substantially inhibited RANKL-induced GPR109A expression and Wnt/ß-catenin signaling in osteoclast precursors and osteoclast differentiation. Resultantly, HA significantly inhibited bone resorption and increased bone mass in wild type mice, but had no additional effects on bone in GPR109A-/- mice compared with their respective untreated control mice. These results suggest an important role for GPR109A during osteoclast differentiation and bone resorption mediating effects of HA and 3-3-PPA on inhibiting bone resorption during skeletal development.

Black Raspberries Suppress Colorectal Cancer by Enhancing Smad4 Expression in Colonic Epithelium and Natural Killer Cells.

Innate immune cells in the tumor microenvironment have been proposed to control the transition from benign to malignant stages. In many cancers, increased infiltration of natural killer (NK) cells associates with good prognosis. Although the mechanisms that enable NK cells to restrain colorectal cancer (CRC) are unclear, the current study suggests the involvement of Smad4. We found suppressed Smad4 expression in circulating NK cells of untreated metastatic CRC patients. Moreover, NK cell-specific Smad4 deletion promoted colon adenomas in DSS-treated ApcMin/+ mice and adenocarcinomas in AOM/DSS-treated mice. Other studies have shown that Smad4 loss or weak expression in colonic epithelium associates with poor survival in CRC patients. Therefore, targeting Smad4 in both colonic epithelium and NK cells could provide an excellent opportunity to manage CRC. Toward this end, we showed that dietary intervention with black raspberries (BRBs) increased Smad4 expression in colonic epithelium in patients with FAP or CRC and in the two CRC mouse models. Also, benzoate metabolites of BRBs, such as hippurate, upregulated Smad4 and Gzmb expression that might enhance the cytotoxicity of primary human NK cells. Of note, increased levels of hippurate is a metabolomic marker of a healthy gut microbiota in humans, and hippurate also has antitumor effects. In conclusion, our study suggests a new mechanism for the action of benzoate metabolites derived from plant-based foods. This mechanism could be exploited clinically to upregulate Smad4 in colonic epithelium and NK cells, thereby delaying CRC progression.

Nonantibiotic prevention and management of recurrent urinary tract infection.

Urinary tract infections (UTIs) are highly prevalent, lead to considerable patient morbidity, incur large financial costs to health-care systems and are one of the most common reasons for antibiotic use worldwide. The growing problem of antimicrobial resistance means that the search for nonantibiotic alternatives for the treatment and prevention of UTI is of critical importance. Potential nonantibiotic measures and treatments for UTIs include behavioural changes, dietary supplementation (such as Chinese herbal medicines and cranberry products), NSAIDs, probiotics, D-mannose, methenamine hippurate, estrogens, intravesical glycosaminoglycans, immunostimulants, vaccines and inoculation with less-pathogenic bacteria. Some of the results of trials of these approaches are promising; however, high-level evidence is required before firm recommendations for their use can be made. A combination of these agents might provide the optimal treatment to reduce recurrent UTI, and trials in specific population groups are required.

ALternatives To prophylactic Antibiotics for the treatment of Recurrent urinary tract infection in women (ALTAR): study protocol for a multicentre, pragmatic, patient-randomised, non-inferiority trial.

BACKGROUND: At least half of all adult women will experience infective cystitis (urinary tract infection: UTI) at least once in their life and many suffer from repeated episodes. Recurrent urinary tract infection (rUTI) in adult women is usually treated with long-term, low-dose antibiotics and current national and international guidelines recommend this as the 'gold standard' preventative treatment. Although they are reasonably effective, long-term antibiotics can result in bacteria becoming resistant not only to the prescribed antibiotic but to other antimicrobial agents. The problem of antimicrobial resistance is recognised as a global threat and the recent drive for antibiotic stewardship has emphasised the need for careful consideration prior to prescribing antibiotics. This has led clinicians and patients alike to explore potential non-antibiotic options for recurrent UTI prevention. DESIGN /METHODS: This is a multicentre, pragmatic, patient-randomised, non-inferiority trial comparing a non-antibiotic preventative treatment for rUTI in women, methenamine hippurate, against the current standard of daily low-dose antibiotics. Women who require preventative treatment for rUTI are the target population. This group is comprised of those with a diagnosis of rUTI, defined as three episodes in 1 year or two episodes in 6 months, and those with a single severe infection requiring hospitalisation. Participants will be recruited from secondary care urology / urogynaecology departments in the UK following referral with rUTI. Participants will be followed up during a 12-month period of treatment and in the subsequent 6 months following completion of the prophylactic medication. Outcomes will be assessed from patient recorded symptoms, quality of life questionnaires and microbiological examination of urine and perineal swabs. The primary outcome is the incidence of symptomatic antibiotic-treated UTI self-reported by participants during the 12-month period of preventative treatment. Health economic outcomes will also be assessed to define the cost-effectiveness of both treatments. A qualitative study will be conducted in the first 8 months of the trial to explore with participants/non-participants' and recruiting clinicians' views on trial processes and identify potential barriers to recruitment, reasons for participating and non-participation and for dropping out of the study. DISCUSSION: The study was commissioned and funded by the National Institute for Health Research (NIHR) and approved under the Medicines and Healthcare products Regulatory Agency (MHRA) notification scheme as a 'Type A' study. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number (ISRCTN), registry number: ISRCTN70219762 . Registered on 31 May 2016.

Methenamine hippurate for preventing urinary tract infections.

BACKGROUND: Methenamine salts are often used as an alternative to antibiotics for the prevention of urinary tract infection (UTI). OBJECTIVES: To assess the benefits and harms of methenamine hippurate in preventing UTI. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library), MEDLINE (from 1950), EMBASE (from 1980), reference lists of articles and abstracts from conference proceedings without language restriction. Manufacturers' of methenamine salts were contacted for unpublished studies and contact was made with known investigators. Date of last search: September 2006 SELECTION CRITERIA: Randomised controlled trials (RCT) and quasi-RCTs of methenamine hippurate used for the prevention of UTIs in all population groups were eligible. A comparison with a control/no treatment group was a prerequisite for selection. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI). An exploration of heterogeneity and a detailed description of results, grouped by population, was undertaken. MAIN RESULTS: Thirteen studies (2032 participants) were included. Six studies (654 patients) reported symptomatic UTI and eight studies (796 patients) reported bacteriuria. Overall, study quality was mixed. The overall pooled estimates for the major outcome measures were not interpretable because of underlying heterogeneity. Subgroup analyses suggested that methenamine hippurate may have some benefit in patients without renal tract abnormalities (symptomatic UTI: RR 0.24, 95% CI 0.07 to 0.89; bacteriuria: RR 0.56, 95% CI 0.37 to 0.83), but not in patients with known renal tract abnormalities (symptomatic UTI: RR 1.54, 95% CI 0.38 to 6.20; bacteriuria: RR 1.29, 95% CI 0.54 to 3.07). For short-term treatment duration (1 week or less) there was a significant reduction in symptomatic UTI in those without renal tract abnormalities (RR 0.14, 95% CI 0.05 to 0.38). The rate of adverse events was low. AUTHORS' CONCLUSIONS: Methenamine hippurate may be effective for preventing UTI in patients without renal tract abnormalities, particularly when used for short-term prophylaxis. It does not appear to work in patients with neuropathic bladder or in patients who have renal tract abnormalities. The rate of adverse events was low, but poorly described. There is a need for further large well-conducted RCTs to clarify this question, particularly for longer term use for people without neuropathic bladder.

Preventing catheter-related bacteriuria: should we? Can we? How?

Up to 25% of hospitalized patients undergo urinary catheterization, and about 5% develop bacteriuria each day of catheterization. Catheter-related bacteriuria is associated with increased morbidity and mortality. We performed an evidence-based synthesis of the literature on preventing catheter-associated urinary tract infections (UTIs) to develop recommendations for clinicians. Catheterization should be avoided when not required and when needed, should be terminated as soon as possible. Use of suprapubic and condom catheters may be associated with a lower risk of UTI than use of urethral catheters. Aseptic catheter insertion and a properly maintained closed drainage system are crucial to reducing the risk of bacteriuria. Instillation of antimicrobial agents into the bladder or urinary drainage bag and rigorous meatal cleansing seem to be of little benefit. Use of urinary catheters coated with silver alloy may reduce the risk of UTI. Systemic antimicrobial drug therapy seems to prevent UTIs, but primarily for patients catheterized for 3 to 14 days. Antibiotic drug prophylaxis is especially valuable in patients undergoing transurethral resection of the prostate or renal transplantation. Using these methods, urinary catheter-associated UTI can often be prevented for weeks, but not longer terms.

Lack of effect of ascorbic acid, hippuric acid, and methenamine (urinary formaldehyde) on the copper-reduction glucose test in geriatric patients.

Ascorbic acid and hippuric acid (from cranberry juice) are commonly used to acidify the urine for the purpose of enhancing the degradation of therapeutic methenamine mandelate to urinary formaldehyde. A study was made of 27 nondiabetic geriatric patients with indwelling Foley catheters and chronic bacteriuria who were treated with methenamine mandelate (4 gm), ascorbic acid (4 gm), and cranberry cocktail (1 liter) daily. All of 972 urine samples showed formaldehyde in mean concentrations between 14 and 25 microgram/ml. No glucose was found when the urine was tested by the copper-reduction method. In vitro false positive reactions reported in the literature do not appear to be duplicated as an in vivo problem.

Methenamine hippurate for preventing urinary tract infections.

BACKGROUND: Methenamine salts are often used for the prevention of urinary tract infection (UTI). OBJECTIVES: To assess the effectiveness of methenamine hippurate in preventing UTI. SEARCH STRATEGY: 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. SELECTION CRITERIA: 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. DATA COLLECTION AND ANALYSIS: 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. MAIN RESULTS: 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. REVIEWER'S CONCLUSIONS: 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.

Urinary antiseptics in asymptomatic bacteriuria of pregnancy.

A screening programme for the detection of asymptomatic bacteriuria in patients attending an antenatal clinic is described. The results obtained from the use of urinary antiseptics in a controlled trial over a period of two years are presented. The number of patients developing clinical pyelonephritis, fetal maturity at delivery and birth weight were recorded for treatment and control groups and compared with the equivalent results obtained from the total population of patients seen at the clinic.

The effect of short-term high-dose treatment with methenamine hippurate of urinary infection in geriatric patients with indwelling catheters. I. The preparation and morphology of a quantified urine sediment.

A quantified sediment of the urine from patients with indwelling catheters was prepared by fixation of 0.1 ml urine in 0.9 ml 2% glutaraldehyde immediately after sampling. Slide preparations were then made from 0.2 ml of the glutaraldehyde suspensions by means of a cytocentrifuge. Bacteria and epithelial cells were properly contrasted by the May-Grünwald-Giemsa stain but haematoxylin-eosin and the Papanicolaou stain were superior as regards leukocyte morphology. It is suggested that glutaraldehyde-cytocentrifuge preparations of the urine cytology may be useful in the evaluation of urinary infection and in the evaluation of the therapy of urinary infection.

The effect of short-term high-dose treatment with methenamine hippurate of urinary infection in geriatric patients with indwelling catheters. II. Evaluation by means of a quantified urine sediment.

The urine sediment of 12 geriatric patients with indwelling catheters was quantified by the glutaraldehyde-cytocentrifuge method prior to, during and after a clinical trial of methenamine hippurate (MH), 2 g x 3 daily given for 34 days as the sole therapeutic agent for the urinary tract infection. The median leukocyte concentration in the urine of these patients was 100 cells/microliter (Q1 - Q3 50-350), i.e. tenfold higher than the upper normal limits reported in healthy probands. The median bacteriuria in the control period was 12 x 10(5) bacteria/ml urine, interquartile range 10-60 x 10(5) bacteria/ml and extreme individual values 300-500 x 10(5) bacteria/ml. Hematuria, defined as greater than or equal to 24 erythrocytes/microliter urine, was not prominent and could not be correlated with MH treatment, nor with catheter changes. The reported observations suggest that short-term high-dose treatment with MH as sole therapeutic agent reduced pyruria and bacteriuria in the group of patients studied.