FIG. 4.

Efficacy of levofloxacin against B. anthracis under “partially humanized” animal pharmacokinetic profiles. (Upper panels) Treatment regimens in which levofloxacin was administered at the beginning of each 24-h dosing interval (AUC = 23 mg · h/liter) and a smaller dose at 12 h (AUC = 6.1 mg · h/liter; partially humanized [A]) or in which levofloxacin was administered in three decreasing doses at 8-h intervals (AUCs = 22, 7.5, and 4.5 mg · h/liter, respectively; partially humanized [B]). For each regimen, the solid line depicts the theoretical pharmacokinetic profile of the partially humanized regimens with datum points for the measured levofloxacin concentrations. The broken line shows an equivalent human exposure (AUC₂₄ = 36 mg · h/liter; AUC₂₄/MIC = 300). (Lower panel) Effect of the human exposure and “partially humanized” animal exposures on B. anthracis cultures.