Kidney Stone Management

Acute Pain Management

The American College of Physicians recommends administering intramuscular diclofenac 75 mg as first-line therapy for acute kidney stone pain, which provides superior pain relief within 30 minutes while avoiding dependence risks 1, 2
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
Opioids, such as hydromorphine, pentazocine, or tramadol, should be reserved only when NSAIDs are contraindicated due to cardiovascular disease, gastrointestinal comorbidities, hypertension, renal insufficiency, heart failure, or peptic ulcer risk 1, 2

All patients require medical assessment within 30 minutes to exclude life-threatening conditions 1
Immediate hospital admission is mandatory for patients with shock or fever, failure to respond to analgesia within one hour, abrupt recurrence of severe pain after initial relief, patients over 60 years, or women with delayed menses 1, 3
Sepsis with obstructed kidney requires urgent decompression via percutaneous nephrostomy or ureteral stenting, which is a urologic emergency that cannot wait 2, 3

For stones ≤10 mm, offer observation with medical expulsive therapy (MET) using alpha-blockers, such as tamsulosin, 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, 1, 2
The maximum duration of conservative treatment is 4-6 weeks from initial presentation 1, 2
For stones >10 mm, most stones will require surgical treatment, with ureteroscopy (URS) being the first-line surgical treatment for distal ureteral stones 5, 2
Patients must be informed that URS has better stone-free rates with a single procedure but higher complication rates compared to shock wave lithotripsy (SWL) 5

Instruct patients to drink fluids targeting urine output of at least 2.5 liters daily to promote stone passage 1, 3
Coffee, tea, wine, and orange juice are associated with lower stone risk, while sugar-sweetened beverages should be avoided 3

For calcium stones, offer thiazide diuretics, such as hydrochlorothiazide, to patients with hypercalciuria and recurrent calcium stones 6, 3
For 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 6, 1, 2
For cystine stones, first-line treatment includes increased fluid intake, sodium/protein restriction, and urinary alkalinization to pH 7.0, with cystine-binding thiol drugs, such as tiopronin, added if unresponsive to dietary modifications 6, 1

Obtain stone analysis at least once when available, as composition directs specific preventive measures 7, 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

Obtain periodic blood testing to assess for adverse effects in patients on pharmacological therapy, such as thiazides, allopurinol, and tiopronin 7
Obtain repeat stone analysis when available, especially in patients not responding to treatment, as stone composition may change 7

Do not use opioids as first-line therapy for acute kidney stone pain, as NSAIDs are superior and avoid dependence risks 1, 2, 3
Do not delay admission for fever with obstruction, as this represents sepsis requiring urgent drainage 1, 3
Do not prescribe allopurinol as first-line for uric acid stones, as urinary alkalinization is correct initial therapy 6, 1, 2