Urolithiasis Treatment

Alkaline citrate (Sodium & Potassium)

• A urinary alkalinizer used to prevent uric acid or cystine calculi formation
• Also used as an adjuvant w/ uricosuric agents in gout therapy
• Effective in correcting the acidosis of certain renal tubular disorders
• Contraindicated in patients w/ severe renal impairment w/ oliguria or azotemia, untreated Addison’s disease & severe myocardial damage

Allopurinol

• Inhibits xanthine oxidase & reduces the production of uric acid w/o disrupting the biosynthesis of vital purines
• Used in the prevention of gout, renal calculi due to uric acid or calcium oxalate, prophylaxis & treatment of uric acid nephropathy
• Contraindicated in patients w/ idiopathic hemochromatosis & asymptomatic hyperuricemia

Chlorthalidone

• A long-acting antihypertensive/diuretic that enhances the excretion of sodium, chloride ions & water by interfering w/ the transport of sodium ions across the renal tubular epithelium
• Contraindicated in patients w/ known anuria & hypersensitivity to other sulfonamide-derived drugs

Thiazide diuretics (Hydrochlorothiazide)

• Inhibits the sodium reabsorption in the distal tubules & as a result, the excretion of sodium, water, potassium & hydrogen ions increases
• Used as treatment for hypercalciuria & calcium stone recurrence
• Contraindicated in patients w/ known anuria & hypersensitivity to other sulfonamide-derived drugs

Sodium bicarbonate

• Raises blood & urinary pH by dissociation to provide bicarbonate ions, which neutralizes the hydrogen ion concentration
• Used to alkalinize the urine & to titrate the dose to achieve the desired urinary pH
• Contraindicated in patients w/ alkalosis, hypernatremia, severe pulmonary edema, hypocalcemia & unknown abdominal pain

Tiopronin

• An active reducing agent that undergoes a thiol-disulfide exchange w/ cystine & forms a tiopronin-cystine disulfide
• It decreases the amount of soluble cystine in the urine & reduces the formation of cystine calculi
• Contraindicated in patients w/ prior history of developing agranulocytosis, aplastic anemia or thrombocytopenia

Watchful Waiting

• Since most stones are small, about 5 mm in size, the patient is advised for the passage of stones through normal urination, that usually happens w/in 2-3 days
• A collection kit is provided w/ filter & the patient is instructed to collect the passed stone for testing & analysis

Diet therapy

• All stone formers are advised to have a fluid intake that will achieve a urine volume of at least 2.5 liters daily
• Limit sodium intake & consume 1,000-1,200 mg per day
  • Lower calcium diet in the absence of other specific dietary measures increases the risk of stone formation

• Limit the intake of oxalate-rich foods & maintain normal calcium consumption
• Increase the intake of fruits & vegetables
  • Hypocitrituria is common among patients w/ stone disease, w/ a prevalence of 20-60%
  • Promoted by renal tubular acidosis (RTA), chronic diarrhea & carbonic anhydrase inhibitor

• Limiting the intake of non-dairy animal protein may help reduce stone recurrence
  • Patients w/ a history of uric acid stones should be counseled to:
    • Increase the intake of alkali & decrease the intake of acids
    • Increase the urine pH
    • Reduce the urinary acidity