Urinary calculi and the consumption of analgesics.

There are many causes for stones in the urinary tract (Melick and Henneman, 1958; Boyce and Bradshaw, 1961 ; Maurice and Henneman, 1961). These include the presence of urinary solutes in abnormally high concentrations (Hodgkinson and Pyrah, 1958 ; Nordin and Robertson, 1966), a variety of factors diminishing their solubility (Elliot et al., 1961 ; Howard et al., 1962; Metcalfe-Gibson et al., 1965), and anatomical abnormalities favouring their precipitation (Boyce and King, 1963). In about half the patients no cause for stone formation is found (Melick and Henneman, 1958). During a recent survey of 266 consecutive patients referred for the investigation of urinary calculi it was found that 43 of them gave a history of heavy consumption of analgesics (Lavan et al., 1966). A search of the literature showed that in spite of many papers on the nephrotoxicity or otherwise of these compounds (Gilman, 1964; Dawborn et al., 1964; Rubenstein et al., 1964; Fordham et al., 1965; Lancet, 1966) there appears to have been no systematic investigation into the association between stones in the urinary tract and the regular consumption of analgesics. Such an association is reported in this paper.