[Clinical study of Urocit-K: a slow releasing potassium citrate]

Citrate is recognized as one of the inhibitors of urinary stone formation. If the urinary citrate and pH could be elevated by the supply of potassium citrate, the recurrence of stone formation would hopefully be prevented. Urocit-K is a kind of slow releasing preparation of potassium citrate. The pharmacokinetics of Urocit-K is investigated in this study, which included two groups: 1) the hypocitraturia group consisting of twenty patients and 2) the normal volunteer group consisting of ten persons. Urokit-K was administered to patients in 10 mEq doses, t.i.d. for 2 weeks. Comparison of urinary biochemistry was done prior to, and one week after administration of the Urocit-K. In the normal volunteer group, the pharmacokinetics of Urocit-K was determined by urinary pH, K, and citrate. Determinations were made six times a day (every 2-hours for first 8 hours, 7- and 9- hours for the last 16 hours) with Urocit-K for comparison. This study indicated that Urocit-K increases urinary pH, K, and citrate in hypocitraturic patients. In the normal volunteer group, Urocit-K deserves its slow-releasing property shown by a constant increase of urinary pH and K for the first 8 hours; and urinary citrate for almost 24 hours. No apparent complications, such as gastrointestinal upset or cardiopulmonary discomfort were observed. In conclusion, Urocit-K is an excellent preparation of potassium citrate and a good choice for prevention of stone recurrence.