POTENTIAL NEPHROTOXICITY OF INTRAVENOUS INFUSIONS OF NAFTIDROFURYL OXALATE

We report two cases of acute renal failure in patients with arterioscl erosis obliterans treated by intravenous infusion of naftidrofuryl oxa late. At renal biopsy the histological lesions were identical with tho se found in ARF due to hyperoxaluria of other causes, revealing tubula r epithelial necrosis and massive intratubular precipitation of calciu m oxalate monohydrate (C1) crystals. A second study was then conducted in four other patients with arteriosclerosis obliterans to evaluate s erum and urinary levels of oxalate, and crystalluria during the intrav enous administration of 800 mg of naftidrofuryl oxalate per day for 10 days. During the course of treatment, the serum and urinary oxalate l evels were found to increase substantially, with the gradual onset of massive C1 crystalluria. These results indicate that naftidrofuryl oxa late was responsible for the acute renal failure in the first two pati ents. High intravenous doses of naftidrofuryl oxalate must be used cau tiously, with close surveillance of renal function.