Absolute bioavailability of moxifloxacin

Moxifloxacin (BAY 12-8039) is an investigational 8-methoxy-fluoroquinolone with broad-spectrum gram-positive and gram-negative activity. To determine the absolute bioavailability of moxifloxacin, this open-label, randomized, crossover study compared the pharmacokinetic characteristics of a single 10 0-mg dose administered either orally or intravenously as a 60-minute infusi on in 10 healthy male volunteers (mean age [+/- SD], 29.3 +/- 7.1 years; me an weight [+/- SD], 77.7 +/- 8.7 kg). Geometric mean values for oral/IV mox ifloxacin were as follows: peak serum concentration, 1.15/1.34 mg/L, and ar ea under the concentration-time curve over 48 hours, 9.86/10.89 mg.h/L. The geometric mean absolute bioavailability of oral moxifloxacin was 91.8%. Me an renal clearance was approximately 2.3 L/h after administration of both t he single oral and IV formulations, which suggests lack of active tubular s ecretion of moxifloxacin. Both the oral and IV formulations were well toler ated, with 5 repented possible or probable drug-related adverse events; the y included headache, nausea, and localized urticaria. In summary, a single oral dose of moxifloxacin was extensively absorbed in healthy young men. Fu rther studies are necessary in actual patients to confirm the viability of IV to oral conversion at the same dose of moxifloxacin.