Triamterene stone: advantage of crystallographic analysis

Microscopic crystallographic analysis of renal calculi provides clinically useful information concerning the pathogenesis of stone disease and is, therefore, superior to conventional chemical analysis of stones. The advantages of crystallography, performed at a centralized, experienced stone-analysis center, are highlighted by the recent discovery of triamterene deposits in kidney stones. Deposits of other medications and their metabolites have also been uncovered. Two case reports are presented, the clinical implications of these and related findings are discussed.