Efficacy and Safety of Using MPC-5971 in Subjects Undergoing Shock Wave Lithotripsy

After SWL treatment subjects will be randomized to receive either MPC-5971 or placebo. Two tablets of MPC-5971 or placebo will be taken orally twice a day (bid). This will give a daily dosage equal to 40 mEq of potassium, 20 mEq of magnesium and 60 mEq of citrate. MPC-5971 or placebo will be taken bid for 90 days beginning immediately after SWL treatment.

After SWL treatment subjects will be randomized to receive either MPC-5971 or placebo. Two tablets of MPC-5971 or placebo will be taken orally twice a day (bid). This will give a daily dosage equal to 40 mEq of potassium, 20 mEq of magnesium and 60 mEq of citrate. MPC-5971 or placebo will be taken bid for 90 days beginning immediately after SWL treatment.