Inhibition of cholesterol absorption by neomycin, benzodiazepine derivatives and ketoconazole.

Neomycin and a benzodiazepine derivative (RO16-0521) inhibit similarly cholesterol absorption in man but the serum cholesterol level is reduced only by neomycin. Reason(s) for the difference are unknown. Ketoconazole inhibits 14 alpha-demethylation of lanosterol so that cholesterol synthesis is reduced. The agent inhibits also cholesterol absorption. The serum cholesterol level is reduced by about 20%, the lowering being potentiated by a simultaneous cholestyramine treatment.