Search

A survey of 763 patients with rheumatoid arthritis and 145 with osteoarthritis in six clinics in New Zealand showed no association between aspirin intake and a score designed to detect analgesic nephropathy. Analgesic nephropathy was diagnosed clinically in three patients taking APC (aspirin, phenacetin, and caffeine or codeine or both) and in one who took aspirin and phenylbutazone and was suspected in one who took aspirin and paracetamol. Isolated aspirin was not implicated. The study showed that most people can take large quantities of salicylates without renal injury.The findings are, however, consistent with the view that there is a risk from APC compounds taken in large quantity, but the numbers at risk in this study were small. Aspirin may have an additive effect with other analgesics in causing renal damage. An increased frequency of urinary tract symptoms in those taking analgesics requires further investigation.

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.