Pharmacology: Ofloxacin exerts its bactericidal action by inhibiting DNA gyrase, an enzyme necessary for bacterial DNA replication, in susceptible organisms.
Microbiology: Ofloxacin is active in vitro against many gram-positive aerobic bacteria, including penicillinase-producing, non-penicillinase-producing, and some methicillin-resistant staphylococci. It is also active in vitro against most gram-negative aerobic bacteria, including Enterobacteriaceae and Pseudomonas aeruginosa. It also has some activities in vitro against Chlamydia, Mycoplasma, Mycobacterium, Plasmodium and Rickettsia.
Ofloxacin has some activities against gram-positive and gram-negative anaerobic bacteria; however, high concentrations of the drug are generally required for in vitro inhibition and most of these organisms are considered resistant to the drug. This includes Clostridium and Bacteroides groups.
Pharmacokinetics: Ofloxacin is rapidly and almost completely absorbed from the gastrointestinal tract following oral administration. Peak serum concentrations are generally attained within 0.5-2 hrs. It is widely distributed into body tissues and fluids following oral administration, and is concentrated within neutrophils, achieving concentrations in these cells that may be up to 8 times greater than extracellular concentrations. Almost 80% of ofloxacin is excreted unchanged in urine and a small percentage of the dose is excreted in urine as metabolites and in feces. In healthy adults with normal renal function, its elimination half-life in the terminal phase averages 4-8 hrs, although renal impairment will increase its serum concentrations and prolong its half-life.