Comparative antibacterial spectrum of trimethoprim and brodimoprim.

Brodimoprim is a new 2,4-diaminobenzylpyrimidine that selectively inhibits bacterial and resistance plasmid dihydrofolate reductases to a similar or greater extent than trimethoprim. Brodimoprim reaches equivalent levels in the serum as trimethoprim for the same dosage regimens but, unlike trimethoprim, brodimoprim has a long half-life. Brodimoprim has a similar antibacterial spectrum to trimethoprim against bacterial species normally sensitive to this class of drugs although it is not active against aerobic bacteria that are normally inherently trimethoprim-resistant, such as Pseudomonas spp. Against a range of strains of the Enterobacteriaceae trimethoprim was slightly more active, although in an in vivo murine model brodimoprim had a significantly better cure rate. Brodimoprim was 2-4-fold more active against several strains of Neisseria, Nocardia, Vibrio cholerae, Bacteroides and other anaerobes. In particular the MIC90 values of brodimoprim for Clostridium and Fusobacterium spp were lower than those of trimethoprim.