Battling Multidrug Resistant UTIs With Methenamine Hippurate

Recently, Federal Practitioner talked with Rebecca McAllister, MS, FNP-BC, about her role in treating complicated urinary tract infections (UTIs) in elderly patients at the Community Living Center of the Bay Pines VA Healthcare System in Florida. The original July 2014 Case in Point, “Recurrent Multidrug Resistant Urinary Tract Infections in Geriatric Patients,” discussed 4 case studies, which suggested the safety and efficacy of treatment with methenamine hippurate.

Federal Practitioner: Much of the focus in your article was on the use of methenamine in Norway and Sweden and a lack thereof in the U.S. How are multidrug resistant UTIs generally treated in the U.S., and how could this be handled differently?

Rebecca McAllister, MS, FNP-BC: Because of the increased rates of bacterial resistance, treating recurrent UTIs prophylactically with low-dose antibiotics is no longer the standard of care. Currently, multidrug resistant UTIs are treated with broad-spectrum antibiotics, that organisms are susceptible to. The promise of methenamine relies on the bacteria not developing resistance to it; in turn, long-term use in patients does not contribute to developing resistance.

FP: Is methenamine hippurate readily available within the VA, and what are the guidelines surrounding its use?

RM: Methenamine is on the VA formulary available in 1-gm doses. Standard guidelines per Micromedex are for prophylaxis of recurrent UTIs, as mentioned in the article, and contraindicates use in patients with impaired renal function, although specific parameters are not identified, because testing was never done with geriatric patients.

FP: Of the 4 patients discussed in the article, 3 were aged > 89 years and the fourth was aged exactly 89 years. Was this a coincidence, or does the success of methenamine in this oldest-old cohort highlight UTI recurrence rate late in life, the failed efficacy of other drugs over time, or both?

RM: The success of methenamine highlights both UTI recurrence rate late in life and the failed efficacy of other drugs over time. The primary patient group in these case studies was composed of homebound veterans.

FP: At the beginning of the discussion portion of your article, following 4 case studies, you mention, “Patients with similar profiles to those discussed in this report were treated with less dramatic results.” How do you, as a family nurse practitioner, consider treatment a success, and how might this differ from expectations set by a medical facility?

RM: As is always the challenge with preventive interventions, it is difficult to measure what does not happen. Successful treatment for recurrent UTIs is lack of recurrence, also asymptomatic colonization vs a symptomatic UTI, which can be measured by a urinalysis is a success. In the oldest of the old, delayed hospitalization for urosepsis, reduced risk of falls, and increased mortality are also successes. Cost savings to the health care system by administering an inexpensive preventive medication vs very expensive IV antibiotic therapy, another success. The observed changes in bacterial resistance in patients treated with methenamine offers great hope in the battle against bacteria.

Ms. McAllister coauthored the July 2014 article, “Recurrent Multidrug Resistant Urinary Tract Infections in Geriatric Patients,” with Janice Allwood, MS, ARNP, CUNP.

Ms. McAllister is a Community Living Center family nurse practitioner and Ms. Allwood is an advanced registered nurse practitioner in Urology Surgery, both at the Bay Pines VA Healthcare System in Florida.