The potential use of cholestyramine to reduce the risk of developing Clostridium difficile-associated diarrhoea in patients receiving long-term intravenous ceftriaxone.

Intravenous pharmacotherapy with the third-generation cephalosporin ceftriaxone is unfortunately associated with a relatively high incidence of Clostridium difficile-associated diarrhoea. Cholestyramine (colestyramine) is an anion-binding resin which can bind luminal C.difficile toxin A (TcdA) and toxin B (TcdB) and which may be beneficial in the treatment of recurrent antibiotic-associated pseudomembranous colitis. We therefore hypothesised that concomitant oral cholestyramine might reduce the risk of C.difficile-associated diarrhoea in patients receiving long-term intravenous ceftriaxone. A pilot study was carried out in which it was found that only three out of 46 (6.5%) such patients being treated with 2 g ceftriaxone daily for Lyme borreliosis, who also received 4 g cholestyramine daily, developed C.difficile-associated diarrhoea. This is smaller than a published report of the incidence of this complication in six out of 26 (23.1%) patients following 1-3 days' treatment with 1 g intravenous ceftriaxone, but without oral cholestyramine (p=0.06). We therefore recommend that a larger, double-blind placebo-controlled trial be carried out to test this hypothesis.