Long term urinary stone management begins with prevention, and prevention typically entails minor lifestyle and dietary changes. As with any preventable medical condition, treatment should be viewed as a measure of last resort.
Diagnostic laboratory procedures can be useful in formulating specific dietary suggestions as well as indicating appropriate medications and other courses of action. Some of these are described here.
Analysis of the passed stone material will identify kidney stone type as one of the following:
calcium oxalate (most common)
uric acid (usually not visible by X-ray)
struvite (usually associated with infection)
cystine (very hard and difficult to fragment)
Twenty-four hour urine collection is employed to measure total volume, levels of calcium, oxalate, uric acid, citrate, magnesium, sodium, phosphate, and pH.
Blood testing provides measurement of serum calcium, uric acid, phosphate, potassium, chloride, bicarbonate, albumin, and creatinine levels. Elevated serum calcium may signal parathyroid dysfunction and require serum parathyroid hormone level.
One should typically maintain a 24 hour urine volume of at least 2 quarts. This may require drinking up to 3 to 3-1/2 quarts of fluids per day. High urine flow helps prevent stones by washing harmful crystals from the urinary system.
Low protein, low salt, and no added dietary calcium may also lessen the likelihood of stones. This means cutting back on meat, fish, and chicken. Diets low in salt may help decrease urinary calcium excretion. There may be benefits from avoiding grapefruit juice and large portions of high oxalate foods such as spinach, sweet potatoes, rhubarb, okra, beets, beet greens, and refried beans.
Specific Therapy and Medication
Treatment for calcium stones with a thiazide diuretic will decrease urinary calcium excretion. Low potsassium associated with taking thiazides is treated by adding potassium dietary supplement.
Treatment for uric acid stones also calls for low protein diet to reduce purines and urinary uric acid. Maintaining an alkaline urine is mandatory. Allopurinol may be added to correct high urinary uric acid.
Treatment for cystine stones requires keeping urine output at 2 to 3 quarts daily. Decreasing dietary protein and salt is advised. Cystine crystal formation is inhibited in alkaline urine. Potassium citrate may be added for alkalinization.
Treatment for struvite stones requires keeping the urine bacteria free. Long term antibiotics may be necessary to achieve this.