The effect of diphosphonate on calcium phosphate crystallization in urine in vitro

Abstract

Disodium ethane 1 hydroxy 1,1 diphosphonate (EHDP) was added to human urine in vitro and tested for its effect on nucleation, crystal growth and crystal dissolution of brushite (CaHPO4 2H2O), the probable nidus for certain calcium containing renal stones. The EHDP (0.5 to 8 mg of P/l) increased the formation product of brushite, indicating an inhibition of nucleation of brushite. It inhibited the crystal growth of brushite in every urine specimen tested. Finally, it facilitated the crystal dissolution of brushite in some urine specimens. Thus, EHDP might be clinically useful in the prevention of renal stone formation.