Prophylaxis of cystine calculi by low dose of alpha-mercapto-propionyl-glycine administered every other day.

In a case of typical cystinuria type I with left kidney hypoplasia and bilateral calculosis, calculi were dissolved by means of alpha-mercapto-propionyl-glycine and prophylaxis of the calculosis was performed by the same drug continuously administered in two divided doses (10-4 mg.kg-1.day-1) for 9 years, without urolithiasis. Then, the alpha-mercaptopropionyl-glycine every other day in one dose, 4 mg.kg-1.day-1, for two years was administered without calculosis. The arbitrary discontinuation of the drug by the patient was followed after 6 months from a right ureteral calculosis with transitory renal insufficiency. In our case the administration of a low dose of alpha-mercapto-propionyl-glycine every other day was useful in cystine calculosis prophylaxis.