Uric Acid Metabolism in Calcium Oxalate Stone Disease
The concept of a direct relationship of uric acid to oxalate metabolism in the formation of the calcium oxalate crystals in urine is becoming well recognised. This work was done to identify the importance of uric acid abnormalities in patients who develop pure calcium oxalate stones. Seventy-nine patients who passed stones or had surgery done for the removal of pure calcium oxalate or predominantly calcium oxalate stones were included. They were classified into whewellite and weddellite stone groups. Fifty age and sex matched normals formed the control group. A detailed study of the biochemical parameters of these patients was done to look for metabolic abnormalities. The number of biochemical assessments ranged from one occasion to 13 with a mean of 3.2 in the patients. The uric acid levels were compared between patients who formed pure calcium oxalate monohydrate and pure weddellite. All patients who showed high uric acid level in urine or blood were treated with allopurinol in a dose ranging from 100-300 mg/day. Associated oxalate problems were corrected with pyridoxine 40-240 mg/day.