Effects of diclofenac on ceftriaxone pharmacokinetics in humans

The effects of diclofenac, a nonsteroidal antiinflammatory drug, on the biliary and urinary excretion of ceftriaxone were evaluated in subjects with a T drain in the common bile duct. The kinetic study was carried out on the sixth postoperative day of treatment with ceftriaxone alone (2 g intravenously; group 1) or ceftriaxone combined with diclofenac (50 mg every 12 h orally from postoperative days 3 to 6; group 2). A significant increase in the elimination half-life of ceftriaxone was observed in group 2 patients. Diclofenac caused a significant rise in ceftriaxone biliary excretion. This increase was not sufficient to balance the significant deficit of urinary excretion of ceftriaxone.