What are the treatment options for kidney stones?

Kidney Stone Treatment

For acute kidney stones, use NSAIDs as first-line pain management, offer medical expulsive therapy with tamsulosin for stones >5mm in the distal ureter, and pursue conservative management for uncomplicated stones up to 10mm for 4-6 weeks before considering surgical intervention. 1

Acute Management

Pain Control

• NSAIDs are the first-line treatment for acute kidney stone pain due to superior efficacy, fewer side effects, and lower risk of dependence compared to opioids 1
• Reserve opioids as second-choice analgesics only when NSAIDs are contraindicated or ineffective 1

Conservative vs. Interventional Approach

• Conservative management is appropriate for uncomplicated ureteral stones up to 10mm 1
• Medical expulsive therapy (MET) with alpha-blockers (tamsulosin) is recommended, particularly for stones >5mm in the distal ureter 1
• The maximum duration of conservative treatment should be 4-6 weeks from initial clinical presentation 1
• For stones that fail to pass spontaneously after this period, surgical intervention is required based on stone size and location 1

Surgical Options

• When conservative management fails, interventions include extracorporeal shock wave lithotripsy, percutaneous nephrolithotomy, ureteroscopy, ureteral stents, or nephrostomy tubes depending on stone characteristics and location 2

Long-Term Medical Management Based on Stone Type

Calcium Stones (Most Common - 61% of cases)

• Thiazide diuretics should be offered to patients with high or relatively high urine calcium and recurrent calcium stones 1
• Potassium citrate therapy should be offered to patients with recurrent calcium stones and low or relatively low urinary citrate 1
• Dietary sodium restriction is advised to maximize the hypocalciuric effect of thiazides 3

Common pitfall: Using supplemental calcium rather than dietary calcium, as supplemental calcium may be associated with increased stone formation risk 1

Uric Acid Stones (12% of cases)

• Potassium citrate is first-line therapy to raise urinary pH to approximately 6.0, which enhances uric acid solubility 1, 3
• Allopurinol can be used in calcium oxalate stone formers with hyperuricosuria 4

Common pitfall: Prescribing allopurinol as first-line therapy for uric acid stones instead of urinary alkalinization with potassium citrate 1, 3

Cystine Stones

• First-line therapy includes increased fluid intake (target at least 4 liters per day), restriction of sodium and protein intake, and urinary alkalinization 1, 3
• Potassium citrate should be offered to raise urinary pH to approximately 7.0 3
• Cystine-binding thiol drugs such as tiopronin should be offered to patients unresponsive to dietary modifications and urinary alkalinization 3
• Tiopronin is preferred over d-penicillamine due to better efficacy and fewer adverse events 3

Brushite Stones

• Potassium citrate is first-line pharmacological therapy for brushite stone formers with hypocitraturia or elevated urine pH 1
• Thiazide diuretics should be offered to brushite stone formers with hypercalciuria 1
• The combination of potassium citrate and thiazide diuretics can be used for patients with persistent stone formation 1

Struvite Stones

• Complete surgical removal coupled with appropriate antibiotic therapy is necessary 4
• Urease inhibitors (acetohydroxamic acid) may be beneficial, though side effects may limit use 3
• Patients should be monitored for reinfection 5

Essential Prevention Strategies for All Stone Types

Hydration

• Increased fluid intake to achieve urine volume of at least 2.5 liters daily is critical for both symptom management and stone prevention 5, 1, 6
• For cystine stones specifically, target at least 4 liters per day 3

Initial Workup

• Obtain detailed medical and dietary history to identify predisposing conditions, habits, or medications 5, 1
• Order serum chemistries including electrolytes, calcium, creatinine, and uric acid 5, 1
• Perform urinalysis including dipstick and microscopic evaluation to assess urine pH, indicators of infection, and identify crystals 5, 1
• Obtain urine culture if urinalysis suggests UTI or if patient has history of recurrent UTIs 5, 1
• Imaging studies should be obtained to quantify stone burden, with renal ultrasonography as the recommended first-line modality 5, 1
• Stone analysis should be obtained at least once, as composition may implicate specific metabolic or genetic abnormalities 5

Monitoring and Follow-Up

Metabolic Testing

• High-risk or recurrent stone formers should consider 24-hour urine collection for metabolic evaluation 5
• A single 24-hour urine specimen for stone risk factors should be obtained within six months of initiating treatment to assess response to dietary and/or medical therapy 1, 3
• After initial follow-up, obtain 24-hour urine specimen annually or with greater frequency depending on stone activity 1, 3

Safety Monitoring

• Periodic blood testing should be performed to assess for adverse effects in patients on pharmacological therapy, such as hypokalemia with thiazides or hyperkalemia with potassium citrate 1, 3
• Repeat stone analysis should be obtained when available, especially in patients not responding to treatment 1, 3

Specialist Referral

• Schedule follow-up with urology or nephrology for comprehensive stone management 5

Key Pitfalls to Avoid

• Neglecting to address underlying metabolic abnormalities that contribute to stone formation 1
• Not considering the type of stone when determining appropriate medical therapy 1
• Using sodium citrate instead of potassium citrate, which may increase urine calcium excretion 3
• Failure to monitor for medication side effects 3
• Inadequate fluid intake, which increases risk of stone recurrence 3