These analgesics contained aspirin or other NSAIDs combined with phenacetin, paracetamol, or salicylamide, and caffeine or codeine. In the 1950s, Spühler and Zollinger reported an association between kidney injury and the chronic use of phenacetin. They noted that chronic users of phenacetin had an increased risk of developing specific kidney injuries, namely renal papillary necrosis and chronic interstitial nephritis. This condition was dubbed analgesic nephropathy and was attributed to phenacetin, although no absolute causative role was demonstrated. With further reports of the increased risk of kidney injury with prolonged and excessive phenacetin use, however, phenacetin was banned in several countries between the 1960s and 1980s. As the use of phenacetin declined, so too did the prevalence of analgesic nephropathy as a cause of end-stage kidney disease. Data from Switzerland, for example, demonstrated a decline in the prevalence of analgesic nephropathy among people with end-stage kidney disease, from 28% in 1981 to 12% in 1990. An autopsy study performed in Switzerland suggested that the prevalence of analgesic nephropathy in the general population has likewise decreased; the prevalence was 3% in 1980 and 0.2% in 2000. While these data demonstrate that analgesic nephropathy has been all but eliminated in some regions, in other regions the condition persists. Notably, in Belgium, the prevalence of analgesic nephropathy among people having dialysis was 17.9% in 1984 and 15.6% in 1990. Michielsen and de Schepper suggest that analgesic nephropathy persists among people in Belgium having dialysis not due to non-phenacetin analgesics, but because Belgium accepts a higher proportion of elderly people for dialysis. According to these authors, a greater proportion have analgesic nephropathy because a greater percentage of people in Belgium having dialysis have been exposed to long-term use of phenacetin. Terminology The term analgesic nephropathy usually refers to damage induced by excessive use of combinations of these medications, specifically combinations that include phenacetin. For this reason, it is also called analgesic abuse nephropathy. Murray prefers the less judgmental analgesic-associated nephropathy. Both terms are abbreviated to the acronym AAN, by which the condition is also commonly known. References External links Kidney diseases Pain management