Renal Damage Associated with Chronic Phenacetin Overdosage

Abstract

Two patients exhibiting renal damage associated with chronic phenacetin overdosage are reported. Some of the extensive European experience with this association is reviewed. The surprising paucity of American publications in this regard is noted. Because symptoms of "phenacetin nephritis" are relatively insignificant and non-specific early in the disease, one must resort to direct questioning of patients with impaired renal function and/or urinary tract infection, to establish a diagnosis. Especially is this the case in patients with necrotizing papillitis. Noteworthy features of our cases are: a history of peptic ulcer, severe metabolic acidosis disproportionate to the degree of azotemia, the presence of urinary tract infection, histologic evidence of interstitial nephritis associated with pyelonephritis, the mildness of the proteinuria, the absence of hypertension, and the presence in the urine, of large numbers of "glitter" cells and macrophages. Both patients improved upon discontinuing the phenacetin-containing analgesics and treating their urinary infections. One patient had large numbers of doubly retractile crystals in necrotic papillae from her kidney. While definite proof that phenacetin causes renal damage has not been forthcoming, it is felt that the bulk of evidence favours such a relationship.