Pharmaco-epidemiological considerations in patients with arthritis and vascular disease of the kidney.

Non-steroidal anti-inflammatory drugs (NSAIDs) may produce acute renal failure, papillary necrosis and interstitial nephritis. These adverse drug reactions are rare but have been reported in patients with congestive heart failure, cirrhosis, renal parenchymal disease, lupus nephritis and hypertension. All these conditions may be associated with hypovolaemia and an activated renin-angiotensin system, when renal blood flow and glomerular filtration depend on local renal prostaglandin biosynthesis. A severe impairment of renal function may occur when this synthesis is inhibited by NSAID treatment. It is possible that 1 in 100 of elderly patients have renal parenchymal disease, 1 in 100 arteriolar nephrosclerosis, 1 in 200 unilateral or bilateral renal artery stenosis and an unknown number suffer from atheroembolic renal disease. Fortunately, only a small proportion of 'at risk' patients given NSAIDs appear to develop renal failure. Perhaps bilateral renal disease or salt depletion are necessary factors? Whatever the explanation, NSAIDs should be used with caution in the elderly.