Eligibility Criteria:
Inclusion criteria:
* Male or female subject aged \> or equal to 18 to \< or equal to 70.
* Subject has undergone a computerized tomography (CT) scan within 30 days of the screening visit.
* Subject has been diagnosed with single unilateral renal calculus (target treatment stone).
* Target treatment stone, is presumed to be of calcium composition and/or uric acid composition.
* Target treatment stone is between \> or equal to 5 and \< or equal to 15 mm in diameter.
* Contra lateral kidney may hold a clinically inconsequential size calculus that does not require concurrent SWL treatment.
* Both kidneys are anatomically normal.
* An appropriate candidate for SWL, determined by treating physician.
* Female subjects with a negative pregnancy test, hysterectomy, tubal ligation or non-child bearing potential (post-menopausal).
* Female subjects of child bearing potential with a negative pregnancy test and taking appropriate birth control for the duration of the study.
* Urine is pyuria negative and nitrite negative on dipstick and/or negative upon microscopic evaluation.
* Subject must voluntarily consent to participate in this study and provide his/her written informed consent prior to start of any study-specific procedures.
Exclusion Criteria:
* Current or past history of cystine stones or infection stones.
* Renal insufficiency, defined as serum creatinine value outside of the normal reference range.
* Currently has or had hyperkalemia within the past six months, defined as serum potassium outside of the normal reference range.
* Currently has or had hypermagnesemia within the past six months, defined as serum magnesium outside of the normal reference range.
* Active urinary tract infection.
* Renal calculi in an anatomically abnormal kidney; horseshoe shape, ureteropelvic junction obstruction or calyceal diverticulum.
* Altered urinary tract anatomy such as a transplant kidney, urinary reconstruction or congenital anomaly.
* Blood coagulopathies and or taking anticoagulants (warfarin, coumarin, heparin).
* Taking salicylate (aspirin), including low dose aspirin for cardio-prophylaxis or other NSAID (OTC) that may increase bleeding time, within the past 7 days.
* History of complications with previous SWL; pyelonephritis, perinephric hematoma.
* Unsuccessful SWL treatments for previous stone within the past six months.
* Currently has or previously had ulcers of the esophagus, stomach and/or small intestines.
* Chronic diarrhea or has a history of diarrhea.
* Bowel disease such as Crohn's disease, Celiac disease, fat malabsorption or Sprue.
* Undergone any bariatric surgery procedures.
* Obese, defined as BMI \>30.
* Uncontrolled hypertension defined as subjects taking medication specific for hypertension or subject not on medication with systolic blood pressure above 140 and diastolic above 90.
* Adrenal insufficiency (i.e., Addison's disease), adrenal tumors, and/or subjects on adrenal hormone replacement therapy.
* Taking potassium-sparing diuretics (triamterene, amiloride, spironolactone, Midamor®, Aldactone®, Dyrenium®, Eplerenone®).
* Taking potassium supplements (Rx or OTC) within the past 15 days.
* Taking magnesium supplements (Rx or OTC) within the past 15 days.
* Taken potassium citrate supplements (Rx or OTC) within the past 30 days.
* Subject taking anticholinergic medications at entry (dicyclomine, atropine, scopolamine, oxybutynin, tolerodine, Cogentin®, Sinemet®, Robinal®, Kenadrin®, Artane®, Enablex®, Detrol®, Vesicare®, Sanctura®, Ditropan®, Oxytrol®, Bentyl®, Byclomine®, Dibent®, Di-Spaz®, or Dilomine®). (Subjects may be prescribed anticholinergics as standard of care with use of stents post entry.)
* Subject is has taken gastrointestinal enzyme replacement therapy or proton pump inhibitors within past 30 days (Ultrase®, Creon®, Viokase®, Pancrease® MT, pancrelipase agents, Aciphex®, Nexium®, Prevacid®, Protonix®, Zegerid® Prilosec OTC®, Kapidex®, rabeprazole, esomeprazole, lansoprazole, pantoprazole, omeprazole, dexlansoprazole).
* Women who are pregnant or lactating.
* Subjects with a known hypersensitivity to potassium, magnesium, citrate or any excipients in the drug formulation