Papillary necrosis in experimental analgesic nephropathy.

A proprietary aspirin, phenacetin, and caffeine preparation given to rats in a dose equivalent to that taken by patients with analgesic nephropathy produced papillary necrosis in 55%. There was a higher incidence in rats deprived of fluids overnight.Papillary necrosis was not noted in rats receiving twice as much phenacetin.These findings support the argument that phenacetin should not be singled out as the substance responsible for analgesic nephropathy in man.