Bladder urothelium in nephropathy associated with analgesics

A history of ingestion of large quantities of analgesics in patients having clinical and radiographic features of chronic interstitial nephritis leads to the diagnosis of analgesic nephropathy. In analgesic nephropathy the renal damage possibly occurs from a high concentration of analgesics and/or their metabolites. Since urinary concentrations of analgesics and their metabolites are also high, urinary bladder wall may be similarly damaged. Bladder urothelium was examined in 20 patients. Ten control patients with uremia, hypertension, or bladder neck obstruction showed normal histology. Two of the 5 patients with analgesic nephropathy had brownish pigmentation of bladder. All 5 analgesic nephropathy patients showed chronic inflammation similar to that found in 5 patients with bacterial infections. It is suggested that pigmentation of bladder wall and/or chronic inflammation of bladder mucosa of unknown etiology when found in a patient with chronic interstitial nephritis, would support the diagnosis of analgesic nephropathy.