A retrospective review assessing the efficacy and safety of nitrofurantoin in renal impairment

Background: Nitrofurantoin (NF) is an antibiotic commonly used to treat uncomplicated urinary tract infections (UTIs). Although NF is contraindicated in patients with an estimated glomerular filtration rate (GFR) of less than 60 mL/min, the evidence demonstrating its lack of efficacy and an increased rate of adverse reactions in these patients is marginal. Methods: A retrospective chart review was conducted to determine the efficacy and safety of NF in patients with a UTI and an estimated GFR < 50 mL/min (impaired renal function group) compared to > 50 mL/min (control group). Results: A total of 356 patients met our inclusion criteria. The Modified Cockcroft-Gault equation was used to estimate GFR. The point estimate for cure rate in the impaired renal function group was 71% (95% CI 63-79), versus 78% (95% CI 73-84) for the control group. Conclusions: Similar NF cure rates were observed in patients with impaired renal function (estimated GFR > 50 mL/min) and patients in the control group (estimated GFR > 50 mL/ min). The occurrence of adverse events was comparable between the 2 groups.