Orbifloxacins baktericide virkning skyldes hæmning af enzymerne DNA - topoisomerase II (DNA- gyrase) og DNA - topoisomerase IV, som er nødvendige for dannelsen og vedligeholdelsen af bakterielt DNA.
The bactericidal action of orbifloxacin results from interference with the enzymes DNA topoisomerase II (DNA-gyrase) and DNA topoisomerase IV which are needed for the synthesis and maintenance of bacterial DNA.