Prevention of biliary stent occlusion by ursodeoxycholic acid plus norfloxacin: a multicenter randomized trial.

We report a prospective randomized multicenter trial that tested the efficacy of combining ursodeoxycholic acid and norfloxacin in the prevention of polyethylene stent clogging in patients with obstructive jaundice due to an unresectable malignancy at the level of the common bile duct. After insertion of a 10-Fr straight polyethylene stent, patients were allocated to receive oral treatment with ursodeoxycholic acid and norfloxacin, or conservative treatment. The primary outcome measure was stent blockage within six months. Thirty-three patients (group I) received ursodeoxycholic acid and norfloxacin, and 29 received conservative treatment (group II). At six months, cumulative stent patency rate did not differ significantly between group I (47+/-11%, mean +/- SE, median 149 days) and group II patients (24+/-10%, mean +/- SE, median 100 days, P = 0.23, log-rank test). Four stents were clogged by ursodeoxycholic acid. Survival did not differ between the two groups. Combined therapy with ursodeoxycholic acid and norfloxacin failed to improve stent patency. Moreover, ursodeoxycholic acid can cause stent obstruction.