Clinics & Inpatient Care Units

Renal Services - Kidney Stone Prevention Clinic

Risk factors for kidney stones

Stone recurrence is a common problem for kidney stone patients. When no treatment is given to first time stone patients, around 15 per cent will have another stone in one year and 50 per cent will have a stone in five to 10 years. Simple measures can lower the risk of forming stones - this is the goal of our clinic.

The chance of forming kidney stones is related to factors such as:

  • genetics
  • sex
  • age
  • metabolic disturbances within the body
  • urinary tract infections
  • eating habits
  • fluid intake

Prevention of kidney stones

The following lists the stone type and specific circumstances with diet and medication changes, which may be used to prevent recurrences. The type of stone may be found by analyzing stones passed in the urine. Physicians and dietitians will be able to suggest a treatment plan after the completion of blood and urine tests.

Calcium

General measures: increase fluid, decrease salt, oxalate and meat protein intake, moderate calcium intake
Potassium citrate: citrate is an inhibitor of stone growth
Thiazide diuretic: lowers the amount of calcium in the urine
Magnesium: this element is believed to be an inhibitor of stone formation
Cellulose phosphate: binds to calcium in the intestine for cases of high urinary calcium due to increased calcium absorption




Uric Acid

General measures: increase fluid, decrease meat, fish, poultry and salt
Urine pH: sodium bicarbonate or potassium citrate raises the pH of urine to solubilize uric acid for excretion
Allopurinol: lowers the amount of uric acid in the blood and urine



Cystine

General measures: increase fluid intake (3-4L/day)
Urine pH: cystine is more soluble in alkaline urine (a high pH)
Penicillamine, Alpha-mercaptoproplonylglycine (MPG) or Captopril: increases the solubility of cystine in the urine



Struvite

General measure: currently no dietary recommendation for the prevention of struvite stones. The infected struvite stone must be removed to control urinary tract infection. Future urinary infections should be treated early and effectively to prevent recurrent stone either with antibiotics or acetohydroxamic acid.



Inflammatory bowel disease

Medications and supplements may be used to help manage inflammatory bowel disease and kidney stones such as cholestyramine, calcium supplements, potassium citrate and magnesium supplements.