Nonsteroidal antiinflammatory drugs and acute renal failure in elderly persons

Renal prostaglandin inhibition by nonsteroidal antiinflammatory drugs (NSAIDs) may decrease renal function, especially under conditions of low effective circulating volume. To evaluate the risk of important deterioration of renal function due to this effect, the authors performed a nested case-control study using Tennessee Medicaid enrollees aged greater than or equal to 65 years in 1987-1991. Cases were patients who had been hospitalized with community-acquired acute renal failure; they were selected on the basis of medical record review of Medicaid enrollees with selected discharge diagnoses. Information on the timing, duration, and dose of prescription NSAIDs used, demographic factors, and comorbidity was gathered from computerized Medicaid-Medicare data files. Of the 1,799 patients with acute renal failure (4.51 hospitalizations per 1,000 person-years), 18.1% were current users of prescription NSAIDs as compared with 11.3% of 9,899 randomly selected population controls. After control for demographic factors and comorbidity, use of NSAIDs increased the risk of acute renal failure 58% (adjusted odds ratio = 1.58; 95% confidence interval (CI): 1.34, 1.86). For ibuprofen, which accounted for 35% of NSAID use, odds ratios associated with dosages of less than or equal to 1,200 mg/day, >1,200-<2,400 mg/day, and greater than or equal to 2,400 mg/day were 0.94 (95% Cl: 0.58, 1.51), 1.89 (95% Cl: 1.34, 2.67), and 2.32 (95% Cl: 1.45, 3.71), respectively (test for linear trend: p = 0.009). Prescription NSAID use resulted in an estimated 25 excess hospitalizations associated with renal failure per 10,000 years of use. Thus, NSAIDs represent a relatively uncommon but avoidable cause of acute renal failure in frail elderly persons.