Long-term effects of potassium citrate therapy on the formation of new stones in groups of recurrent stone formers with hypocitraturia.
OBJECTIVE
To compare stone formation rates before (as total rates and during remote periods) and after therapy with potassium citrate in patients with hypocitraturia.


METHODS
The study comprised 15 patients with hypocitraturia only (Group I) and 12 patients with hypocitraturia associated with other abnormalities (Group II), all of whom were recurrent stone formers. Their urine chemistry, including citrate, was measured before and after treatment.


RESULTS
In both groups, the urinary citrate concentration increased significantly to within normal limits during therapy with potassium citrate (P < 0.005). The rate of total stone formation in patients in Group I decreased significantly from 0.7/year before to 0.13/year after treatment (P < 0.005). The corresponding remote stone formation rate before (0.88/year) was significantly greater than the rate after treatment (0.13/year; P < 0.005; follow-up 4.6 +/- 1.9 years). Patients in Group II showed a similar striking decrease in total stone formation rate, from 1.2/year to 0.08/year after treatment (P < 0.005). The corresponding remote stone formation rate (1.66/year) before was significantly greater than that after treatment (0.08/year; P < 0.005; follow-up 4.1 +/- 1.6 years). There was a remission rate of 93% for stone formation over the complete follow-up.


CONCLUSIONS
Potassium citrate appears to be the drug of choice in the long-term treatment of patients with hypocitraturia as it not only decreases the rate of stone formation but also maintains normal citrate levels in the urine.
Whalley
N A
NA
Department of Medicine, Johannesburg Hospital, South Africa.
Meyers
A M
AM
Martins
M
M
Margolius
L P
LP
D000284:Administration, Oral; D002951:Citrates / Q000627:therapeutic use / Q000652:urine*; D019343:Citric Acid; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D016896:Treatment Outcome; D014545:Urinary Calculi / Q000737:chemistry / Q000517:prevention & control* / Q000652:urine
D002951:Citrates; D019343:Citric Acid