IT IS A 4-QUINOLONE ANTIBIOTIC. IT IS RAPIDLY ABSORBED FROM THE G.I. TRACT, PARTIALLY METABOLIZED IN THE LIVER, AND RAPIDLY EXCRETED THROUGH THE KIDNEYS. IT HAS MARKED ANTIBACTERIAL ACTIVITY AGAINST GRAM-NEGATIVE BACTERIA INCLUDING ENTEROBACTER SPECIES, E.COLI, MORGENALLA MORGANII, PROTEUS, MIRABILIS AND PROTEUS VULGARIS. ROSOXACIN IS BACTERICIDAL AND IS EFFECTIVE OVER THE ENTIRE URINARY PH RANGE.