From the Guidelines
To avoid renal stones, increasing fluid intake to achieve at least 2 L of urine per day is recommended. This approach is based on the guideline from the American College of Physicians, which suggests that increased fluid intake spread throughout the day can help prevent recurrent nephrolithiasis 1.
Key Recommendations
- Increase fluid intake to achieve at least 2 L of urine per day to prevent recurrent nephrolithiasis, as recommended by the American College of Physicians 1.
- For patients with active disease in which increased fluid intake fails to reduce the formation of stones, pharmacologic monotherapy with a thiazide diuretic, citrate, or allopurinol may be considered 1.
- Dietary changes, such as reducing dietary oxalate, reducing dietary animal protein and other purines, and maintaining normal dietary calcium, can also help prevent the recurrence of nephrolithiasis 1.
Additional Considerations
- Maintaining a balanced diet rich in fruits and vegetables can help reduce the risk of renal stones.
- Limiting sodium intake, sugar-sweetened beverages, and alcohol can also help prevent stone formation.
- For those with recurrent stones, medications may be prescribed based on stone type, such as potassium citrate for low urinary citrate, thiazide diuretics for high urinary calcium, or allopurinol for uric acid stones 1.
- Maintaining a healthy weight through regular exercise can also reduce the risk of renal stones.
Mechanism of Action
- These measures work by altering urine composition to make it less favorable for crystal formation and aggregation, the fundamental processes in kidney stone development 1.
From the FDA Drug Label
The main inclusion criterion was a history of stone passage or surgical removal of stones during the 3 years prior to initiation of Potassium Citrate therapy. All patients began alkali treatment with 60-80 mEq Potassium Citrate daily in 3 or 4 divided doses Throughout treatment, patients were instructed to stay on a sodium restricted diet (100 mEq/day) and to reduce oxalate intake (limited intake of nuts, dark roughage, chocolate and tea). A moderate calcium restriction (400-800 mg/day) was imposed on patients with hypercalciuria
- To avoid renal stones, patients can follow these measures:
- Stay on a sodium restricted diet
- Reduce oxalate intake
- Impose a moderate calcium restriction if they have hypercalciuria 2
From the Research
Prevention of Renal Stones
To avoid renal stones, several strategies can be employed, including:
- Dietary changes: a regimen low in salt and protein, rich in calcium and magnesium, coupled with adequate fluid intake 3
- Medical treatment: thiazide diuretics, allopurinol, and potassium citrate can be used to treat and prevent calcium oxalate and calcium phosphate stones 3, 4, 5, 6
- Identification and elimination of risk factors: a complete metabolic workup is recommended to identify risk factors such as low urine output, high urinary concentrations of calcium, oxalate, phosphate, and uric acid, and lower excretion of magnesium and citrate 3
Medical Treatment
Thiazide diuretics have been shown to be effective in reducing the risk of recurrent kidney stones:
- Lower doses of thiazide diuretics appear to confer a similar protective effect as higher dose thiazides against the development of kidney stones 7
- Thiazide treatment successfully lowered urine calcium and both calcium oxalate and calcium phosphate supersaturations in both types of stone formers 4
- However, the evidence quality for decrease in kidney calculus incidence using thiazide diuretics is low, and their use in preventing recurrent kidney calculi is not recommended due to adverse effects, poor patient compliance, and economic burden 5
Alternative Treatments
Potassium citrate (K-CIT) has been shown to be effective in reducing urinary calcium excretion in calcium oxalate stone patients with hypercalciuria: