Treatment of gout with allopurinol and sulphinpyrazone in combination and with allopurinol alone.

Successful long-term management of primary gout in the presence of normal renal function may be achieved in most instances by agents which diminish tubular reabsorption of urates, thus permitting increased urinary urate excretion. In recent years the two most widely used uricosuric agents have been probenecid and sulphinpyrazone. The easiest longterm control of gout with the fewest untoward sideeffects has been achieved with sulphinpyrazone (Gutman and Yui, 1957a; Kersley, Cook, and Tovey, 1958; Ogryzlo and Harrison, 1957; Kuzell, Glover, Gibbs, and Blau, 1964). In spite of the relative ease in controlling gout with sulphinpyrazone, any large group of gouty patients will include some in whom the use of uricosuric agents may be impossible or inadvisable because of impairment of renal function or drug intolerance. Some patients, for reasons not yet understood, form tophi much more readily than others, and quite large dosages of uricosuric agents may arrest the formation of tophi without rapidly diminishing those already present. Some form urate stones in the urinary tract so readily that increasing the urinary output of urates may be hazardous. Finally, in secondary gout attended by excessive uric acid formation, the employment of uricosuric agents may be inadvisable because any increase in the already high excretion rate may lead to obstruction of the lower urinary tract by concretions of uric acid. A novel approach in the control of gout is offered by allopurinol, 4-hydroxypyrazolo (3, 4-d) pyrimidine (4-HPP), an inhibitor of xanthine oxidase which prevents conversion of hypoxanthine to xanthine and of xanthine to uric acid (Rundles, Wyngaarden, Hitchings, Elion, and Silberman, 1963; Yu and Gutman, 1964; Rundles, Metz, and Silberman, 1966b). Uric acid available for excretion is diminished, and the relatively more soluble xanthines are readily excreted, thus permitting the use of