How allopurinol can prevent recurrent calcium stones!?

how allopurinol can prevent recurrent calcium stones!?

Uric acid in urine inhibits crystallization inhibitors and precipitate crystallization of calcium.

They promote the production of urine , preventing calcium stones. Allopurinol: This drug inhibits the breakdown of purines to uric acid, lowering the uric acid levels in the urine. Allopurinol is mostly used to prevent uric acid stones