Methenamine hippurate compared with antibiotic prophylaxis to prevent recurrent urinary tract infections in women: the ALTAR non-inferiority RCT.

BACKGROUND: Daily, low-dose antibiotic prophylaxis is the current standard care for women with recurrent urinary tract infection. Emerging antimicrobial resistance is a global health concern, prompting research interest in non-antibiotic agents such as methenamine hippurate, but comparative data on their efficacy and safety are lacking. OBJECTIVE: To assess the clinical effectiveness and cost-effectiveness of methenamine hippurate (Hiprex®; Mylan NV, Canonsburg, PA, USA) compared with current standard care (antibiotic prophylaxis) for recurrent urinary tract infection prevention in adult women. DESIGN: Multicentre, pragmatic, open-label, randomised, non-inferiority trial of 12 months' treatment with the allocated intervention, including an early, embedded qualitative study and a 6-month post-treatment observation phase. The predefined non-inferiority margin was one urinary tract infection per person-year. SETTING: Eight UK NHS secondary care sites. PARTICIPANTS: A total of 240 adult women with recurrent urinary tract infection requiring preventative treatment participated in the trial. INTERVENTIONS: A central randomisation system allocated participants 1 : 1 to the experimental (methenamine hippurate: 1 g twice daily) or control (once-daily low-dose antibiotics: 50/100 mg of nitrofurantoin, 100 mg of trimethoprim or 250 mg of cefalexin) arm. Crossover between treatment arms was permitted. MAIN OUTCOME MEASURES: The primary clinical outcome was incidence of symptomatic antibiotic-treated urinary tract infection during the 12-month treatment period. Cost-effectiveness was assessed by incremental cost per quality-adjusted life-year gained, extrapolated over the patient's expected lifetime using a Markov cohort model. Secondary outcomes included post-treatment urinary tract infections, total antibiotic use, microbiologically proven urinary tract infections, antimicrobial resistance, bacteriuria, hospitalisations and treatment satisfaction. RESULTS: Primary modified intention-to-treat analysis comprised 205 (85%) randomised participants [102/120 (85%) participants in the antibiotics arm and 103/120 (86%) participants in the methenamine hippurate arm] with at least 6 months' data available. During treatment, the incidence rate of symptomatic, antibiotic-treated urinary tract infections decreased substantially in both arms to 1.38 episodes per person-year (95% confidence interval 1.05 to 1.72 episodes per person-year) for methenamine hippurate and 0.89 episodes per person year (95% confidence interval 0.65 to 1.12 episodes per person-year) for antibiotics (absolute difference 0.49; 90% confidence interval 0.15 to 0.84). This absolute difference did not exceed the predefined, strict, non-inferiority limit of one urinary tract infection per person-year. On average, methenamine hippurate was less costly and more effective than antibiotics in terms of quality-adjusted life-years gained; however, this finding was not consistent over the longer term. The urinary tract infection incidence rate 6 months after treatment completion was 1.72 episodes per year in the methenamine hippurate arm and 1.19 in the antibiotics arm. During treatment, 52% of urine samples taken during symptomatic urinary tract infections were microbiologically confirmed and higher proportions of participants taking daily antibiotics (46/64; 72%) demonstrated antibiotic resistance in Escherichia coli cultured from perineal swabs than participants in the methenamine hippurate arm (39/70; 56%) (p-value = 0.05). Urine cultures revealed that during treatment higher proportions of participants and samples from the antibiotic arm grew E. coli resistant to trimethoprim/co-trimoxazole and cephalosporins, respectively. Conversely, post treatment, higher proportions of participants in the methenamine hippurate arm (9/45; 20%) demonstrated multidrug resistance in E. coli isolated from perineal swabs than participants in the antibiotic arm (2/39; 5%) (p = 0.06). All other secondary outcomes and adverse events were similar in both arms. LIMITATIONS: This trial could not define whether or not one particular antibiotic was more beneficial, and progressive data loss hampered economic evaluation. CONCLUSIONS: This large, randomised, pragmatic trial in a routine NHS setting has clearly shown that methenamine hippurate is not inferior to current standard care (daily low-dose antibiotics) in preventing recurrent urinary tract infections in women. The results suggest that antimicrobial resistance is proportionally higher in women taking prophylactic antibiotics. RECOMMENDATIONS FOR RESEARCH: Future research should include evaluation of other non-antibiotic preventative treatments in well-defined homogeneous patient groups, preferably with the comparator of daily antibiotics. TRIAL REGISTRATION: This trial is registered as ISRCTN70219762 and EudraCT 2015-003487-36. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 23. See the NIHR Journals Library website for further project information.

Women with recurrent urine infections often require preventative treatment to reduce the frequency of infection episodes. Daily low-dose antibiotic medication is a guideline-recommended treatment option for these women. There is increasing concern globally regarding antibiotic-resistant infections, which has led researchers to look at alternative treatments. This trial was conducted to find out whether or not taking an alternative treatment that is not an antibiotic [i.e. methenamine hippurate (Hiprex^®; Mylan NV, Canonsburg, PA, USA)] was as effective as the standard daily low-dose antibiotics. A total of 240 women from across the UK took part in the trial. They were divided equally into two groups; half of the women were given methenamine hippurate and the other half were given standard low-dose antibiotics. Both treatments were prescribed to be taken every day for 1 year. To make a fair comparison, people were put into the two groups at random using a computer program. Aspects of the trial that could be improved were identified through telephone interviews with patients and recruiting staff. Feedback from these telephone interviews helped to ensure the successful conduct of the trial. Patients were followed up for 18 months, comprising the 12 months when they were taking treatment and a 6-month follow-up phase after they had finished treatment. We found that the non-antibiotic option of methenamine hippurate was no worse than the current standard treatment of daily antibiotics in preventing urinary tract infection episodes in adult women. For both treatments, patients expressed high levels of satisfaction. One advantage of the methenamine hippurate treatment was that infecting bacteria were slightly less likely to develop resistance to antibiotics. We also evaluated health-care costs of both treatments and found that methenamine hippurate seemed worthwhile to the NHS in the short term, but there was uncertainty over longer-term costs and benefits. These results will help patients with repeated urinary tract infections to decide on treatment options, particularly if they want to avoid prolonged courses of preventative antibiotics.

Alternative to prophylactic antibiotics for the treatment of recurrent urinary tract infections in women: multicentre, open label, randomised, non-inferiority trial.

OBJECTIVE: To test and compare the efficacy of methenamine hippurate for prevention of recurrent urinary tract infections with the current standard prophylaxis of daily low dose antibiotics. DESIGN: Multicentre, open label, randomised, non-inferiority trial. SETTING: Eight centres in the UK, recruiting from June 2016 to June 2018. PARTICIPANTS: Women aged ≥18 years with recurrent urinary tract infections, requiring prophylactic treatment. INTERVENTIONS: Random assignment (1:1, using permuted blocks of variable length via a web based system) to receive antibiotic prophylaxis or methenamine hippurate for 12 months. Treatment allocation was not masked and crossover between arms was allowed. MAIN OUTCOME MEASURE: Absolute difference in incidence of symptomatic, antibiotic treated, urinary tract infections during treatment. A patient and public involvement group predefined the non-inferiority margin as one episode of urinary tract infection per person year. Analyses performed in a modified intention-to-treat population comprised all participants observed for at least six months. RESULTS: Participants were randomly assigned to antibiotic prophylaxis (n=120) or methenamine hippurate (n=120). The modified intention-to-treat analysis comprised 205 (85%) participants (antibiotics, n=102 (85%); methenamine hippurate, n=103 (86%)). Incidence of antibiotic treated urinary tract infections during the 12 month treatment period was 0.89 episodes per person year (95% confidence interval 0.65 to 1.12) in the antibiotics group and 1.38 (1.05 to 1.72) in the methenamine hippurate group, with an absolute difference of 0.49 (90% confidence interval 0.15 to 0.84) confirming non-inferiority. Adverse reactions were reported by 34/142 (24%) in the antibiotic group and 35/127 (28%) in the methenamine group and most reactions were mild. CONCLUSION: Non-antibiotic prophylactic treatment with methenamine hippurate might be appropriate for women with a history of recurrent episodes of urinary tract infections, informed by patient preferences and antibiotic stewardship initiatives, given the demonstration of non-inferiority to daily antibiotic prophylaxis seen in this trial. TRIAL REGISTRATION: ISRCTN70219762.

Open urethroplasty versus endoscopic urethrotomy for recurrent urethral stricture in men: the OPEN RCT.

BACKGROUND: Men who suffer recurrence of bulbar urethral stricture have to decide between endoscopic urethrotomy and open urethroplasty to manage their urinary symptoms. Evidence of relative clinical effectiveness and cost-effectiveness is lacking. OBJECTIVES: To assess benefit, harms and cost-effectiveness of open urethroplasty compared with endoscopic urethrotomy as treatment for recurrent urethral stricture in men. DESIGN: Parallel-group, open-label, patient-randomised trial of allocated intervention with 6-monthly follow-ups over 24 months. Target sample size was 210 participants providing outcome data. Participants, clinicians and local research staff could not be blinded to allocation. Central trial staff were blinded when needed. SETTING: UK NHS with recruitment from 38 hospital sites. PARTICIPANTS: A total of 222 men requiring operative treatment for recurrence of bulbar urethral stricture who had received at least one previous intervention for stricture. INTERVENTIONS: A centralised randomisation system using random blocks allocated participants 1 : 1 to open urethroplasty (experimental group) or endoscopic urethrotomy (control group). MAIN OUTCOME MEASURES: The primary clinical outcome was control of urinary symptoms. Cost-effectiveness was assessed by cost per quality-adjusted life-year (QALY) gained over 24 months. The main secondary outcome was the need for reintervention for stricture recurrence. RESULTS: The mean difference in the area under the curve of repeated measurement of voiding symptoms scored from 0 (no symptoms) to 24 (severe symptoms) between the two groups was -0.36 [95% confidence interval (CI) -1.78 to 1.02; p = 0.6]. Mean voiding symptom scores improved between baseline and 24 months after randomisation from 13.4 [standard deviation (SD) 4.5] to 6 (SD 5.5) for urethroplasty group and from 13.2 (SD 4.7) to 6.4 (SD 5.3) for urethrotomy. Reintervention was less frequent and occurred earlier in the urethroplasty group (hazard ratio 0.52, 95% CI 0.31 to 0.89; p = 0.02). There were two postoperative complications requiring reinterventions in the group that received urethroplasty and five, including one death from pulmonary embolism, in the group that received urethrotomy. Over 24 months, urethroplasty cost on average more than urethrotomy (cost difference £2148, 95% CI £689 to £3606) and resulted in a similar number of QALYs (QALY difference -0.01, 95% CI -0.17 to 0.14). Therefore, based on current evidence, urethrotomy is considered to be cost-effective. LIMITATIONS: We were able to include only 69 (63%) of the 109 men allocated to urethroplasty and 90 (80%) of the 113 men allocated to urethrotomy in the primary complete-case intention-to-treat analysis. CONCLUSIONS: The similar magnitude of symptom improvement seen for the two procedures over 24 months of follow-up shows that both provide effective symptom control. The lower likelihood of further intervention favours urethroplasty, but this had a higher cost over the 24 months of follow-up and was unlikely to be considered cost-effective. FUTURE WORK: Formulate methods to incorporate short-term disutility data into cost-effectiveness analysis. Survey pathways of care for men with urethral stricture, including the use of enhanced recovery after urethroplasty. Establish a pragmatic follow-up schedule to allow national audit of outcomes following urethral surgery with linkage to NHS Hospital Episode Statistics. TRIAL REGISTRATION: Current Controlled Trials ISRCTN98009168. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 61. See the NIHR Journals Library website for further project information.

The urethra carries urine from the bladder to the tip of the penis. Men can develop a condition called urethral stricture when part of the urethra narrows due to scarring. This can lead to difficulties in passing urine and can recur. There are two operations for urethral stricture. The standard approach is endoscopic urethrotomy. The alternative is open urethroplasty. This study wanted to find out which operation was preferable in terms of symptom control, time before further surgery and which operation was best value for the NHS. All aspects of the study were informed by patients. Two hundred and twenty-two men who had received at least one previous operation for stricture took part. The choice of operation was decided by chance (randomisation). Of these men, 113 were randomised to urethrotomy and 109 were randomised to urethroplasty. Following their operation, the men filled in questionnaires every 3­6 months for 2 years about their symptoms and if any further surgery was needed. The two groups were then compared. Of the 222 men who took part, 159 provided enough information for inclusion in the comparison (90 were in the urethrotomy group and 69 were in the urethroplasty group). The improvement over time in urinary symptoms was similar for the two groups. Men in the urethrotomy group were twice as likely to need a further operation over the 2-year study period. Very few men experienced serious complications. This study showed that both operations led to symptom improvement for men with recurrent urethral stricture. Urethroplasty, however, appears unlikely to offer good value for money for the NHS. Men needing treatment for recurrent urethral stricture can use this information to weigh up the pros and cons of each operation to decide with their clinical team which one to undergo.

Surgical Treatment for Recurrent Bulbar Urethral Stricture: A Randomised Open-label Superiority Trial of Open Urethroplasty Versus Endoscopic Urethrotomy (the OPEN Trial).

BACKGROUND: Urethral stricture affects 0.9% of men. Initial treatment is urethrotomy. Approximately, half of the strictures recur within 4 yr. Options for further treatment are repeat urethrotomy or open urethroplasty. OBJECTIVE: To compare the effectiveness and cost-effectiveness of urethrotomy with open urethroplasty in adult men with recurrent bulbar urethral stricture. DESIGN, SETTING, AND PARTICIPANTS: This was an open label, two-arm, patient-randomised controlled trial. UK National Health Service hospitals were recruited and 222 men were randomised to receive urethroplasty or urethrotomy. INTERVENTION: Urethrotomy is a minimally invasive technique whereby the narrowed area is progressively widened by cutting the scar tissue with a steel blade mounted on a urethroscope. Urethroplasty is a more invasive surgery to reconstruct the narrowed area. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was the profile over 24 mo of a patient-reported outcome measure, the voiding symptom score. The main clinical outcome was time until reintervention. RESULTS AND LIMITATIONS: The primary analysis included 69 (63%) and 90 (81%) of those allocated to urethroplasty and urethrotomy, respectively. The mean difference between the urethroplasty and urethrotomy groups was -0.36 (95% confidence interval [CI] -1.74 to 1.02). Fifteen men allocated to urethroplasty needed a reintervention compared with 29 allocated to urethrotomy (hazard ratio [95% CI] 0.52 [0.31-0.89]). CONCLUSIONS: In men with recurrent bulbar urethral stricture, both urethroplasty and urethrotomy improved voiding symptoms. The benefit lasted longer for urethroplasty. PATIENT SUMMARY: There was uncertainty about the best treatment for men with recurrent bulbar urethral stricture. We randomised men to receive one of the following two treatment options: urethrotomy and urethroplasty. At the end of the study, both treatments resulted in similar and better symptom scores. However, the urethroplasty group had fewer reinterventions.