1975 Volume 66 Issue 10 Pages 661-671
With the aim of establishing methods for the prevention of recurrent formation of urinary oxalate containing calculi, the author made the following examinations.
1) Urinary uric acid excretion and urinary pH in 43 cases of urinary oxalate containing calculus.
2) Control of urinary uric acid excretion with 4-hydroxypyrazolo (3, 4-D) pyrimidine (allopurinol).
3) The effect of allopurinol on urinary calcium, magnesium, and phosphate excretion.
4) Prevention of recurrence, and side effects caused by allopurinol in 11 cases of recurrent urinary oxalate containing calculus.
The following results were obtained.
1) Of the 43 patients with urinary oxalate containing stones of unknown etiology except for abnormality of uric acid metabolism, 15 out of 21 cases (71.4%) having a urinary pH value of below 6.0 and urinary uric acid excretion of over 500mg/24 hours showed recurrence of stone formation. On the other hand, recurrence was seen in only 4 out of 22 patients with urinary pH of over 6.0 and urinary uric acid excretion of under 500mg/24 hours.
2) A significant decrease in 24-hour urinary uric acid excretion was seen after administration of 200-300mg/day of allopurinol.
3) Allopurinol administration did not affect serum calcium, magnesium and phosphate concentrations, or urinary phosphate and magnesium excretion; but it caused a significant decrease of urinary calcium excretion, on the average from 107mg to 88mg (p<0.01).
4) Allopurinol was administered to 11 patients with recurrent urinary oxalate containing calculi of unknown etiology except for abnormality of uric acid metabolism (uric acid excretion over 500mg/24 hours, urinary pH less than 6.0) for from 10 to 43 months. New calculus formation was recognized in no case. Except for one case of skin rash, no side effect of allopurinol was experienced.
5) The results suggest that allopurinol affords successful prophylaxis against recurrent oxalate containing stones in patients without explicit cause of stone formation but with a urinary pH of below 6.0 and urinary uric acid excretion of over 500mg per 24 hours.
