A prospective randomised double-blind placebo-controlled trial to assess the effect of diuretics on shockwave lithotripsy of calculi

To assess the effect of diuretics with shockwave lithotripsy (SWL) on the treatment of renal and upper ureteric calculi. Adult patients with a solitary non-obstructive radio-opaque renal or upper ureteric calculus with normal renal function were included. They were prospectively randomised to receive either SWL with placebo or SWL with diuretics (40mg parenteral furosemide) in a double-blind manner with a sample size of 48 patients in each arm. The primary outcomes were the SWL success and failure rates. The secondary outcomes were the number of shocks and sessions. Complete fragmentation was achieved in 89.6% of the patients in the furosemide arm as compared to 81.3% in the placebo arm. Clearance was achieved in 77.1% of the patients in the furosemide arm as compared to 70.8% in the placebo arm. The number of shocks and the number of sessions were higher in the placebo arm. These differences were not statistically significant. The use of diuretics along with SWL treatment of renal and upper ureteric calculi does not show a statistically significant improvement in fragmentation or clearance.