Urinary tract infection after vaginal surgery. Effect of prophylactic treatment with methenamine hippurate. Spinal-injured neuropathic bladder antisepsis (SINBA) trial. Value of urinary prophylaxis with methenamine in gynecologic surgery. [The preventive effect of methenamine hippurate (Haiprex) on urinary infections after short-term catheterization. A clinical study]. Secondary prevention of recurrent urinary tract infections. Comparison of the effect of placebo, methenamine hippurate, nitrofurantoin and trimethoprim alone. Long-term prophylaxis of urinary infections in women: comparative trial of trimethoprim, methenamine hippurate and topical povidone-iodine. Prevention of recurrent urinary infections in women: a comparative trial between nitrofurantoin and methenamine hippurate. Are prophylactic antibiotics necessary during extracorporeal shockwave lithotripsy? Suppression and treatment of urinary tract infection in patients with an intermittently catheterized neurogenic bladder.
One hundred and nine consecutive patients undergoing surgery for uterovaginal prolapse followed by indwelling urinary catheter for 3 days were randomized for prophylactic treatment with methenamine hippurate (MH) or no MH prophylaxis. Significantly less bacteriuria occurred in the MH-treated patient group. In particular, the opportunistic hospital flora appeared to be suppressed by MH treatment. It is suggested that MH prophylaxis, 1 g three times daily, be used in gynecological surgery followed by short-term urinary catheterization. To determine whether Methenamine Hippurate (MH) or cranberry tablets prevent urinary tract infections (UTI) in people with neuropathic bladder following spinal cord injury (SCI).
                Double-blind factorial-design randomized controlled trial (RCT) with 2 year recruitment period from November 2000 and 6 month follow-up.
                In total, 543 eligible predominantly community dwelling patients were invited to participate in the study, of whom 305 (56%) agreed.
                Eligible participants were people with SCI with neurogenic bladder and stable bladder management. All regimens were indistinguishable in appearance and taste. The dose of MH used was 1 g twice-daily. The dose of cranberry used was 800 mg twice-daily. The main outcome measure was the time to occurrence of a symptomatic UTI.
                Multivariate analysis revealed that patients randomized to MH did not have a significantly longer UTI-free period compared to placebo (HR 0.96, 95% CI: 0.68-1.35, P=0.75). Patients randomized to cranberry likewise did not have significantly longer UTI-free period compared to placebo (HR 0.93, 95% CI: 0.67-1.31, P=0.70).
                There is no benefit in the prevention of UTI from the addition of MH or cranberry tablets to the usual regimen of patients with neuropathic bladder following SCI. There is a high risk of postoperative bacteriuria and urinary tract infection after gynecologic surgery. Postoperative asymptomatic bacteriuria often disappears without treatment, but 15-20% of patients still require treatment for postoperative urinary tract infection. This study was carried out to assess the value of prophylactic treatment with methenamine hippurate after routine gynecologic surgery.
                This was a prospective, randomized, double-blind, placebo-controlled clinical trial comprising 145 patients undergoing routine gynecologic laparotomy or vaginal plastic surgery using a Foley catheter for 24 h. Antibiotics were not used. Subjects received 1 g Hiprex or placebo twice daily for 5 days. Urine was cultured preoperatively, at catheter removal, and 2 days later. Patients with positive cultures were not given antibiotics unless they were symptomatic. The follow-up period was 1 month.
                The chi-square test, Fisher exact test, and t-test were used with level of significance at 0.05, and odds ratios with 95% confidence intervals were calculated.
                Asymptomatic bacteriuria was diagnosed in 36 cases (50.0%) in the placebo group and 22 cases (30.1%) in the methenamine group (p = 0.02). Urinary tract infection was diagnosed in 10 cases (13.9%) in the placebo group and two cases (2.7%) in the methenamine group (p = 0.03). There were few adverse events.
                Prophylactic treatment with methenamine hippurate significantly reduces the incidence of postoperative bacteriuria and urinary tract infection. nan 290 patients with recurrent urinary tract infection were treated with either placebo, methenamine hippurate, nitrofurantoin or trimethoprim. 38.9% of the patients had chronic pyelonephritis and 23.8% azotemia. During the follow-up period of 1 year 63.2% recurred in the placebo group, 34.2% in the methenamine hippurate group, 25.0% in the nitrofurantoin group and 10.4% in the trimethoprim group. 62.5% of the recurrences in the trimethoprim group were associated with trimethoprim-resistant strains. However, such strains appeared only in 6.5% of the patients treated with trimethoprim, compared with 16.2% in the placebo, 8.3% in the nitrofurantoin and 11.0% in the methenamine hippurate groups. Side-effects were mild and occurred most frequently in the nitrofurantoin group (13.9%). We randomized 64 patients with a history of recurrent urinary tract infections among 3 regimens of long-term (1 year) prophylactic treatment: 20 were given 100 mg. trimethoprim at night, 25 received 1,000 mg. methenamine hippurate every 12 hours and 19 were asked to cleanse the perineum (especially the periurethral area) twice daily with povidone-iodine solution. The progress of patients in terms of urinary symptoms and/or bacteriuria, changes in periurethral flora, side effects, and hematological and biochemical profiles was followed at regular intervals. All treatments were effective in reducing the incidence of symptomatic attacks when compared to the 12 months immediately before therapy and there was little to choose between the individual regimens on this account. However, trimethoprim was tolerated better than were the other 2 treatment regimens. In the group given trimethoprim most of the breakthrough infections (71.4 per cent) that occurred were caused by trimethoprim-resistant organisms (usually Escherichia coli), while in the other 2 groups the incidence of trimethoprim-resistant organisms causing infection was low (2.7 per cent). Treatment with trimethoprim reduced significantly the periurethral colonization of Escherichia coli. We treated 99 female patients suffering from recurrent urinary infections with either 1 gm. methenamine hippurate every 12 hours or 50 mg. nitrofurantoin every 12 hours for intervals of up to 1 year. Monthly microbiological and clinical surveillance was done. Both treatments were effective in reducing the incidence of symptomatic attacks, with nitrofurantoin being more effective. The protective effect of prophylaxis continued after treatment had stopped, suggesting that a permanent beneficial action had been produced. Especially during the first month of treatment methenamine hippurate was tolerated better than nitrofurantoin: 28 per cent discontinued therapy with the latter owing to nausea. A randomised clinical study was carried out on patients admitted for ESWL treatment in order to establish the requirement for prophylactic treatment with antibiotics during this procedure. Patients with clinical signs of urinary tract infection, evidence of infectious stones or a positive urine culture were excluded. All other patients were consecutively randomised into 3 groups which were given either trimethoprim + sulphamethoxazole or mecillinam (Group A), methenamine hippurate (Group B), or no treatment at all (Group C). Evaluation with respect to clinical signs of infection was done immediately after the treatment and 4 weeks later. In addition, a urine culture was performed 2 weeks after ESWL, i.e. 1 week after completing treatment with antibiotics and methenamine hippurate. With respect to infectious complications there were no differences between Groups A and C, between Groups B and C or between Group A and B+C, whereas an unexplained slightly higher infectious rate was recorded for Group B compared with Group A. In all patients the occurrence of bacteriuria was low (6.7%) despite the fact that almost 30% of patients had a ureteric catheter during the ESWL procedure. Patients with ureteric catheters did not present with more infectious complications than those without. All patients had a bladder catheter during ESWL. It was concluded that prophylactic treatment with antibiotics during ESWL treatment is unnecessary in all situations where an infectious aetiology is unlikely. We evaluated the optimal means of prevention and treatment of urinary tract infections in 46 patients with an intermittently catheterized neurogenic bladder. Suppression with nightly 160 mg. trimethoprim and 800 mg. sulfamethoxazole compared to placebo showed no difference in the rate of symptomatic or total urinary tract infections. Symptomatic urinary tract infections occurred at the same rate whether routine asymptomatic infections were treated or not. Three-day antibiotic treatment of urinary tract infections showed no decrease in the frequency of symptomatic or total urinary tract infections compared to 10-day therapy. The frequency of post-treatment urinary tract infection persistence, relapse and cure was identical in both groups. Suppressive antibiotics, treatment of asymptomatic urinary tract infections and full course antibiotic therapy offered no advantage over placebo, treatment of symptomatic urinary tract infection only and short course therapy in the management of urinary tract infection in patients with an intermittently catheterized neurogenic bladder.
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.