Protective effects of nifedipine and allopurinol on high energy shock wave induced acute changes of renal function.

In a prospective randomized study, the effects of a calcium antagonist (nifedipine) and a xanthine oxidase inhibitor (allopurinal) on high energy shock wave induced impairment of renal function were examined. A total of 40 patients with renal pelvis or caliceal stones undergoing anesthesia-free extracorporeal shock wave lithotripsy (ESWL) without auxiliary measures was randomly assigned to 4 groups. Group 1 received no medication and the others received nifedipine (group 2), allopurinol (group 3) or nifedipine plus allopurinol (group 4), respectively. Nifedipine (20 mg. each) or allopurinol (0.2 gm. each) was given orally 3 times a day for a total of 4 days beginning the night before ESWL. To assess renal function the urinary excretions of beta 2-microglobulin, albumin and Tamm-Horsfall protein were determined by radioimmunoassay. After ESWL there was a significant increase in urinary beta 2-microglobulin and albumin (p < 0.001), and the urinary Tamm-Horsfall protein decreased significantly (p < 0.01) compared with before ESWL in group 1. In groups 2 and 4, however, all of the parameters after ESWL were not significantly different compared with the values before ESWL. Although the levels of urinary beta 2-microglobulin and albumin after ESWL were significantly higher (p < 0.05) than the pre-ESWL levels in group 3, the changes in urinary albumin and Tamm-Horsfall protein were milder in group 3 than in group 1. In addition, the urinary albumin level in group 2 and the urinary beta 2-microglobulin or albumin level in group 4 were less significantly different (p < 0.05) than the levels in group 1. All parameters before ESWL were not significantly different among the groups. Our results indicated that nifedipine and/or allopurinol exhibits a protective effect on high energy shock wave induced renal damage.