Does regular use of non‐steroidal anti‐inflammatory drugs increase the risk of renal disease?

SUMMARY: Some studies have suggested a disturbing incidence of chronic renal failure (CRF) and renal papillary necrosis (RPN) following regular non-steroidal anti-inflammatory drug (NSAID) use. This study was undertaken to assess the prevalence of renal insufficiency in rheumatology patients taking regular NSAIDs and a control group of age-matched subjects who had other chronic illnesses but were not taking regular NSAIDs. Sixty-nine patients with rheumatological disorders and significant NSAID use but no known renal abnormalities were compared with 69 age-matched subjects with non-renal chronic disease who were not taking NSAIDs. Each patient completed a questionnaire regarding NSAIDs and analgesic use, and then had their blood pressure measured along with urinalysis, urine microscopy, serum electrolytes and creatinine and calculated creatinine clearance using the Cockroft-Gault formula. If clinically indicated, patients had further renal imaging to detect structural renal damage. By definition of the study design, rheumatology patients took significantly more NSAIDs than control subjects (P < 0.0001). Twelve patients (19%) in the rheumatology group had renal impairment compared with 10 (17%) in the control group (P= 0.67). Seven patients (10%) in the rheumatology group had microscopic haematuria with or without proteinuria, which was not statistically different to that in the control group (3%, P= 0.09), but isolated microscopic haematuria was detected more commonly in the rheumatology group (11 vs2%, P= 0.03). No patient in either group had clinically apparent RPN, which appeared to be an uncommon complication of chronic NSAID use in rheumatology patients. Chronic renal insufficiency is present in approximately one in five rheumatology patients taking long-term NSAIDs, but this prevalence is no greater than in patients with other chronic illnesses who do not take long-term NSAIDs.