Aspirin, phenacetin, and the kidney: a rheumatism clinic study.

In a rheumatism clinic study in Brisbane, the consumption of aspirin and phenacetin compounds (APC) containing more than one kilogram of aspirin and phenacetin was significantly associated with overt renal papillary necrosis (RPN) and with a renal score, but when more than one kilogram of aspirin was taken without phenacetin there was no such association. Analysis and comparison with the parallel New Zealand study showed an overall risk of RPN of at least 10-6% when more than one kilogram of aspirin was taken in APC form, and 0-3% when aspirin was taken without phenacetin. An additive interaction of phenacetin and aspirin is postulated. It is concluded that phenacetin use should be severely restricted.