Fick et al1 provide some useful recommendations to avoid medications that produce unwarranted toxic effects or drug-related problems in older adults. It is surprising to find that nitrofurantoin was given a high-severity rating because of purported "potential for renal impairment." This assessment was based on group consensus using a modified Delphi method. Group opinions can be misinformed. There is no evidence-based support for this notion. Nitrofurantoin has many potential adverse effects, but I am unaware of reports that it causes renal failure.2,3 Perhaps the intent of the expert panelists was to indicate that nitrofurantoin is contraindicated in patients with renal failure (creatinine clearance <60 mL/min) because of inadequate or subtherapeutic concentrations in the urine. The amount of nitrofurantoin excreted into the urine is directly related to renal function.4 Nitrofurantoin may be ineffective for treatment of urinary tract infections in elderly patients with reduced renal function, but it is not contraindicated because of nephrotoxicity.
Kunin CM. Inappropriate Medication Use in Older Adults: Does Nitrofurantoin Belong on the List for the Reasons Stated?. Arch Intern Med. 2004;164(15):1701. doi:10.1001/archinte.164.15.1701-a