Pharmacokinetics and metabolism of moxifloxacin

Moxifloxacin is a recently developed fluoroquinolone antibiotic. It is rapidly absorbed following oral administration, reaching a mean peak drug plasma concentration (C(max)) of approximately 3.56 mg/l within 2 h after a 400 mg dose. The rate and extent of absorption are not significantly affected by food or elevated gastric pH. Moxifloxacin binds weakly to plasma proteins and penetrates well into most tissue and fluid compartments, with generally higher drug concentrations in tissue and fluid compartments than those observed in plasma. Moxifloxacin is metabolized to an N-sulfate conjugate and an acyl glucuronide in humans. The N-sulfate and the unchanged moxifloxacin are detected in plasma, urine and feces. The acyl-glucuronide is detected in plasma and urine, but not in feces. The plasma elimination half-life ranges from 8.2-15.1 h in healthy individuals. The urinary excretion of the unchanged drug accounts for 19-22% of the given dose. Neither renal nor hepatic impairment significantly affect the pharmacokinetics of moxifloxacin.