Background: Although IDSA recommends nitrofurantoin as first-line treatment for patients with uncomplicated UTIs, it is contraindicated in patients with CrCl<60mL/min due to potential for adverse effects and decreased efficacy. Additionally, CrCl is used to dose nitrofurantoin instead of estimated glomerular filtration rate (eGFR) despite eGFR’s superior accuracy. Elderly patients are classified as complicated UTI cases and often have reduced kidney function, precluding them from nitrofurantoin use.
Methods: This retrospective case series examines the safety and efficacy of nitrofurantoin in elderly patients with CrCl <60mL/min. Community-dwelling patients from a Program of All-inclusive Care for the Elderly (PACE) who were prescribed nitrofurantoin for UTIs between January 2010 to August 2015 were stratified into CrCl and eGFR ranges of <20mL/min, 20-39mL/min, 40-59mL/min, and >60mL/min.
Results: Thirteen patients with a mean age of 85.31 + 9.22 years received oral nitrofurantoin 50mg or 100mg twice daily. Those who completed treatment were on nitrofurantoin for a mean duration of 5.21 ± 2.29 days. Only one case in the series was classified as a possible treatment failure. Seven patients had predisposing medical conditions that may lead to toxicity, but only one patient experienced nitrofurantoin-related adverse effects. This patient fell into the CrCl range of 40-59mL/min (40.1mL/min) and the eGFR range of 40-59mL/min (54.0mL/min).
Conclusion: This case series suggests that there is no appreciable difference in safety or efficacy when using nitrofurantoin to treat UTIs in elderly patients with CrCls as low as 26mL/min and eGFRs as low as 30mL/min.