What are the treatment options for kidney stones?

Treatment Options for Kidney Stones

For acute kidney stone pain, administer intramuscular diclofenac 75 mg as first-line therapy—not opioids—which provides superior pain relief within 30 minutes while avoiding dependence risks. 1, 2

Acute Pain Management

• NSAIDs are the definitive first-line analgesic because they directly decrease ureteral smooth muscle tone and spasm, addressing the underlying pain mechanism rather than just masking symptoms. 1, 2
• Diclofenac 75 mg IM, ibuprofen, or metamizole are all acceptable NSAID options, with diclofenac showing the strongest evidence. 1, 2
• Use the lowest effective NSAID dose to minimize cardiovascular and gastrointestinal risks, and exercise caution in patients with reduced glomerular filtration rate. 2
• Reserve opioids (hydromorphine, pentazocine, or tramadol) only when NSAIDs are contraindicated due to cardiovascular disease, gastrointestinal comorbidities, hypertension, renal insufficiency, heart failure, or peptic ulcer risk. 1, 2
• Avoid pethidine entirely due to high vomiting rates and need for additional analgesia. 2

Immediate Assessment and Emergency Situations

• All patients require medical assessment within 30 minutes to exclude life-threatening conditions. 1
• Immediate hospital admission is mandatory for: 1, 3
  • Shock or fever (potential sepsis)
  • Failure to respond to analgesia within one hour
  • Abrupt recurrence of severe pain after initial relief
  • Patients over 60 years
  • Women with delayed menses
• Sepsis with obstructed kidney requires urgent decompression via percutaneous nephrostomy or ureteral stenting—this is a urologic emergency that cannot wait. 2, 3
• Collect urine for culture before and after decompression, administer antibiotics immediately, and delay definitive stone treatment until sepsis resolves. 2

Conservative Management vs. Surgical Intervention

For Stones ≤10 mm:

• Offer observation with medical expulsive therapy (MET) using alpha-blockers for uncomplicated ureteral stones ≤10 mm when pain is well-controlled, sepsis is absent, and renal function is adequate. 4, 1, 2
• Prescribe tamsulosin or another alpha-blocker, which provides greatest benefit for stones >5 mm in the distal ureter, with stone-free rates of 77.3% versus 54.4% for placebo. 4, 2
• The maximum duration of conservative treatment is 4-6 weeks from initial presentation. 1, 2
• Mandatory periodic imaging is required to monitor stone position and assess for hydronephrosis. 4, 1

For Stones >10 mm:

• Most stones >10 mm will require surgical treatment. 4
• For distal ureteral stones >10 mm, ureteroscopy (URS) is first-line surgical treatment. 2
• For distal stones <10 mm, both URS and shock wave lithotripsy (SWL) are acceptable, though URS yields significantly higher stone-free rates. 4, 2
• Patients must be informed that URS has better stone-free rates with a single procedure but higher complication rates (3-6% ureteral injury, 1-4% sepsis, 1-5% stricture) compared to SWL. 4
• Do not perform routine stenting as part of SWL—it provides no benefit for fragmentation and causes frequent stent-related symptoms. 4, 2

Supportive Care for Home Management

• Instruct patients to drink fluids targeting urine output of at least 2.5 liters daily to promote stone passage. 1, 3, 5
• Coffee, tea, wine, and orange juice are associated with lower stone risk, while sugar-sweetened beverages should be avoided. 3
• Have patients void into a container or tea strainer to catch stones for analysis. 1, 3

Stone Type-Specific Medical Management

Calcium Stones:

• Offer thiazide diuretics (hydrochlorothiazide 25 mg twice daily or 50 mg once daily) to patients with hypercalciuria and recurrent calcium stones. 4, 3
• Offer potassium citrate to patients with hypocitraturia, but use caution to prevent calcium phosphate stone formation by avoiding excessive urinary alkalinization. 4, 3, 5
• Offer allopurinol to patients with hyperuricosuria and normocalciuria (urinary uric acid >800 mg/day), as this reduces recurrent calcium oxalate stones. 4

Uric Acid Stones:

• Potassium citrate is first-line therapy to alkalinize urine to pH ~6.0-7.2, as most patients have low urinary pH rather than hyperuricosuria as the predominant risk factor. 4, 1, 2
• Oral chemolysis with citrate or sodium bicarbonate has an 80.5% success rate. 2
• Do not prescribe allopurinol as first-line for uric acid stones—urinary alkalinization is correct initial therapy. 4, 1, 2
• Patients should monitor urine pH and adjust medication accordingly. 2

Cystine Stones:

• First-line includes increased fluid intake, sodium/protein restriction, and urinary alkalinization to pH 7.0. 4, 1
• Add cystine-binding thiol drugs (tiopronin preferred over d-penicillamine) if unresponsive to dietary modifications or with large recurrent stone burdens. 4, 1, 5

Struvite Stones:

• Complete surgical removal coupled with appropriate antibiotic therapy is necessary. 5
• Monitor patients for reinfection. 4
• The urease inhibitor acetohydroxamic acid (AHA) may be beneficial, though extensive side effects may limit use. 4

Diagnostic Workup

• Obtain stone analysis at least once when available, as composition directs specific preventive measures. 4, 1, 3
• Perform urinalysis with both dipstick and microscopic evaluation to assess urine pH, infection indicators, and identify pathognomonic crystals. 1, 3
• Order serum chemistries including electrolytes, calcium, creatinine, and uric acid to identify underlying metabolic conditions. 1, 3
• Renal ultrasonography is the recommended first-line imaging modality to quantify stone burden, with imaging within 7 days if stone has not passed. 1, 3, 6
• Obtain 24-hour urine collection within six months of initiating treatment for high-risk or recurrent stone formers, then annually or more frequently depending on stone activity. 4, 3

Follow-Up and Monitoring

• Telephone follow-up one hour after initial assessment to verify pain control. 3
• Obtain periodic blood testing to assess for adverse effects in patients on pharmacological therapy (thiazides may cause hypokalemia and glucose intolerance; allopurinol and tiopronin may elevate liver enzymes; potassium citrate may cause hyperkalemia). 4
• Obtain repeat stone analysis when available, especially in patients not responding to treatment, as stone composition may change. 4

Common Pitfalls to Avoid

• Do not use opioids as first-line therapy—NSAIDs are superior and avoid dependence risks. 1, 2, 3
• Do not delay admission for fever with obstruction—this represents sepsis requiring urgent drainage. 1, 3
• Do not prescribe allopurinol as first-line for uric acid stones—urinary alkalinization is correct. 4, 1, 2
• Do not restrict dietary calcium—this may paradoxically increase stone risk by increasing intestinal oxalate absorption. 3
• Do not offer prolonged conservative management beyond 6 weeks without reassessment. 2
• Do not use routine stenting before SWL—it provides no benefit and causes stent-related symptoms. 4, 2