Lack of antibacterial activity of pentoxifylline

Pentoxifylline was inactive when tested against 70 fresh clinical bacterial isolates, as well as when tested alone and in combination with erythromycin, vancomycin, or rifampin against Escherichia coli PC1349 (wild type) and its heptose-deficient outer membrane mutant E. coli PC2040. No antibacterial activity of pentoxifylline or its metabolites could be detected in sera from patients receiving pentoxifylline or its metabolites could be detected in sera from patients receiving pentoxifylline.