Analgesic abuse syndrome: a frequently overlooked cause of reversible renal failure.

The incidence of analgesic nephropathy in the United States is greater than previously reported. Because of the characteristic radiographic features of papillary necrosis, this diagnosis may be made while it is still clinically unsuspected. Early diagnosis is extremely important because cessation of analgesic abuse may avert progressive renal damage. Uncovering the diagnosis calls for special care in obtaining the telltale history. This must be sought in patients with radiographic evidence of papillary necrosis when a history of diabetes mellitus, obstructive uropathy, or sicle cell anemia is absent, or in patients with unexplained nephrocalcinosis or nephrolithiasis.