A Study on the Effection of Potassium Citrate Extended-release Tablets on Urolithiasis Formation or Recurrence

Inclusion Criteria:

• Patients with upper urinary tract calculi surgery and/or ESWL within 3 months；

• Stone free or had residual stone fragments with a less than 4 mm diamete；

• 18-70 years of age; the gender is not limited；

• Agree to take effective contraceptive measures during the study period, and female ofchildbearing age whose pregnancy test is negative；

• Subjects with no mental illness and language dysfunction, can understand the situationof the study and have signed informed consent.

Exclusion Criteria:

• Patients with infectious stones, medical stones and urinary tract obstruction；

• Patients with hyperkalemia (K+＞5.5mmol/L) (or patients with factors or disease thatcan cause hyperkalemia), because the further increase in blood potassium can lead tocardiac arrest. These factors include disease or strenuous exercise, chronic renalfailure, uncontrolled diabetes, acute dehydration, excessive, adrenal insufficiency,extensive tissue failure. Patients who takes potassium sparing diuretics (such astriamterene, spironolactone, amiloride)；

• Patients with gastrointestinal disorders, such as peptic ulcer, severe vomiting,diarrhea, delayed gastric emptying, intestinal obstruction, etc.；

• Combined with cardiovascular, liver, kidney, hematopoietic system, such as severeprimary disease, or known to affect the survival of serious diseases (such as canceror AIDS), or patients with with disabilities mentally or legally；

• Patients with renal insufficiency (1.2 times the upper limit of the normal value ofserum creatinine and urea nitrogen)；

• The recent (within 6 months) with family planners；

• Allergic to this product；

• To participate in other clinical trials in the past three months.