Q: Colestipol and Cholestyramine are used as adjunctive therapy for relapsing C. Diff.  colitis. Which one precaution should be taken in their administration? 


Answer:  Colestipol and cholestyramine are anion-binding resins which are not indicated for primary treatment for C. difficile colitis but are known for decades to be used as adjunct therapy for relapsing infection. But as they are anion-binding resins, they binds oral vancomycin; thus, the resin should be administrated at least 2 to 3 hours apart from the vancomycin.


References: 

1. Taylor NS, Bartlett JG. Binding of Clostridium difficile cytotoxin and vancomycin by anion-exchange resins. J Infect Dis 1980; 141:92

2. Kreutzer EW, Milligan FD. Treatment of antibiotic-associated pseudomembranous colitis with cholestyramine resin. Johns Hopkins Med J 1978; 143:67.