Effect of short-term high-dose treatment with methenamine hippurate on urinary infection in geriatric patients with an indwelling catheter

Abstract

An evaluation has been made of the clinical and laboratory effects of short-term (34 days), high-dose (2g x 3 daily) treatment with methenamine hippurate (MH) of 14 geriatric patients with an indwelling catheter and clinical features of urinary tract infection. During MH treatment the number of catheter changes was halved, each catheter remaining in situ for an average of 12.0 days as compared to 6.2 days in the pre-treatment control period and 5.2 days in the post-treatment control period; the difference is significant (p = 0.008; Friedman two-way analysis of variance). Urine pH was reduced (pH 7.0--6.5--7.0; p = 0.01) and the standard bicarbonate in blood was slightly elevated (24.1--25.7--25.0 mmol/l; p= 0.008) during the MH treatment period, when compared to pre- and post-treatment control periods. It is suggested that MH treatment reduced the complications associated with indwelling catheters due to reduction in urine pH, bacteriuria, and pyuria. Blockage of catheters is thought to be due to intraluminal salt precipitations with trapping of clumps, and is primarily not correlated with urine viscosity.

Diagnosis, Prevention, and Treatment of Catheter-Associated Urinary Tract Infection in Adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America

“…The foul smell of urine around patients with urine incontinence is thought to be attributable mainly to the production of ammonia from urea by bacterial ureases [114]. Foul-smelling and/or cloudy urine is often interpreted as warranting antimicrobial treatment in catheterized patients with bacteriuria [115].…”

Preventing Catheter-Related Bacteriuria

“…Using a before-and-after intervention design, oral methenamine hippurate therapy (2-6 g/d) was found to reduce the incidence of bacteriuria, 77,78 symptomatic UTI, 79 and pyuria. 80 One large, nonrandomized, comparative trial 81 found that patients receiving methenamine hippurate had significantly fewer courses of antibiotic drug therapy for symptomatic UTI and less frequent mechanical catheter complications. Other studies, 82 however, have not found any benefit of methenamine therapy in suppressing catheter-associated bacteriuria.…”

The Urine Smell around Patients with Urinary Incontinence

“…First, antibiotics were re placed by methenamine hippurate, which has no ecological side effects. The function time of silicone-coated latex catheters was dou bled during treatment with methenamine hippurate but bacteriuria and pyuria per sisted [15,16], Then an attempt was made to make latex catheters bactericidal by coating with copper metal; the attempt has, however, not been a clinical success hitherto [17],…”

“…The use of indwelling catheters in the management of aged patients with urinary' incontinence is associated with a non-controllable nosocomial situation [7,15,16]. It is suggested that catheters be replaced by diapers whenever possible.…”

“…It was derived from studies on the problems of patients with indwelling cathe ters [15,16]. One basic problem with in dwelling catheters is that they introduce a massive persistent bacteriuria and pyuria in the urinary tract.…”