Nephropathy as a hazard of analgesic abuse

Analgesic nephropathy is discussed. It has been estimated that 5-7% of all patients with chronic renal failure have a history of excessive analgesic use. Chronic analgesic abusers are predominantly women (3:1), and the peak incidence is between the ages of 40-60. Most analgesic abusers have some psychoneurosis with a history of headaches, backaches, arthritis, or ulcers. Several mechanisms for this nephrotoxicity have been proposed. It is thought that the ingestion of aspirin with phenacetin modifies the metabolism or alters the renal tissue response to one of these two drugs in such a manner as to increase toxicity. It has been proposed that the oxidative metabolites of phenacetin act in conjunction with aspirin to cause papillary necrosis. Chronic renal failure, a history of excessive analgesic use, radiological evidence of papillary necrosis, and clinical evidence of hematuria and mild proteinuria may confirm the diagnosis of analgesic nephropathy. Pharmacists should be aware of the indicence of analgesic nephropathy, and the general profile of patients who abuse analgesics. Early detection and cessation of analgesic use may avert progressive renal failure. Pharmacists should advise patients on the long-term complications of chronic analgesic use.