What medications are prescribed for nephrolithiasis (kidney stones)?

From the Guidelines

Medications for kidney stones primarily include thiazide diuretics, citrate, or allopurinol to prevent recurrent nephrolithiasis, as recommended by the American College of Physicians 1. When considering treatment options, it's essential to note that approximately 80% of adults with kidney stones have stones consisting primarily of calcium oxalate, calcium phosphate, or both.

• The American College of Physicians recommends pharmacologic monotherapy with a thiazide diuretic, citrate, or allopurinol to prevent recurrent nephrolithiasis in patients with active disease in which increased fluid intake fails to reduce the formation of stones 1.
• Thiazide diuretics, such as hydrochlorothiazide, can reduce calcium excretion and are often used to prevent calcium stones.
• Citrate, such as potassium citrate, helps prevent calcium and uric acid stones by making urine less acidic.
• Allopurinol lowers uric acid production and is used to prevent uric acid stones. Adequate hydration, with a goal of at least 2 L of urine per day, is also crucial in preventing recurrent nephrolithiasis, as it helps to dilute the concentration of lithogenic factors in the urine 1.
• Increasing fluid intake spread throughout the day can help achieve this goal.
• Dietary changes, such as reducing dietary oxalate and animal protein, can also help prevent stone formation. It's essential to note that the choice of medication and treatment approach should be individualized based on the patient's specific stone type, medical history, and other factors, with the goal of reducing morbidity, mortality, and improving quality of life.

From the FDA Drug Label

A fluid intake sufficient to yield a daily urinary output of at least 2 liters and the maintenance of a neutral or, preferably, slightly alkaline urine are desirable to (1) avoid the theoretical possibility of formation of xanthine calculi under the influence of therapy with allopurinol tablets and (2) help prevent renal precipitation of urates in patients receiving concomitant uricosuric agents

• Allopurinol is given for kidney stones, specifically to help prevent renal precipitation of urates.
• Patients should be encouraged to increase fluid intake during therapy to prevent renal stones.
• The goal is to maintain a neutral or slightly alkaline urine to help prevent renal stone formation 2

From the Research

Medications for Kidney Stones

The following medications are used to treat and prevent kidney stones:

• Thiazide diuretics: used to treat calcium stone formers with idiopathic hypercalciuria 3
• Potassium alkali therapy: used to treat hypocitraturia, but caution should be taken to prevent potential risk of calcium phosphate stone formation 3
• Allopurinol: used in calcium oxalate stone formers with hyperuricosuria 3
• Tiopronin: used to treat cystine stones if urinary alkalinization and adequate fluid intake are insufficient 3
• Alpha-blockers: used to increase stone clearance rate in ureteral stones ≤10 mm treated without lithotripsy, and in renal or ureteral stones treated with lithotripsy 4
• Citrates: prescribed for patients with recurrent calcium stones 5
• Antispasmodic medications: used to augment fluid and pain medications in the acute management of kidney stones 6

Prevention of Kidney Stones

To prevent kidney stones, the following medications and lifestyle modifications can be used:

• Increased fluid intake: recommended for all patients to prevent stone formation 3, 5
• Dietary modifications: adjusted based on individual metabolic abnormalities, such as low oxalate diet and increased dietary calcium intake for absorptive hyperoxaluria 3
• Thiazide diuretics: prescribed for patients with recurrent calcium stones 5
• Allopurinol: prescribed for patients with recurrent calcium stones 5
• Citrates: prescribed for patients with recurrent calcium stones 5

Specific Stone Types

The following medications are used to treat specific types of kidney stones:

• Cystine stones: Tiopronin can be used if urinary alkalinization and adequate fluid intake are insufficient 3
• Struvite stones: complete surgical removal coupled with appropriate antibiotic therapy is necessary 3
• Uric acid stones: urine should be alkalinized by eating a diet high in fruits and vegetables, taking supplemental or prescription citrate, or drinking alkaline mineral waters 6
• Calcium phosphate stones: urine should be acidified; cranberry juice or betaine can lower urine pH 6