[Antituberculosis effect of levofloxacin]

Abstract

Objective: Assess the activities of levofloxacin (LVLX) against Mycobacterium tuberculosis both in vitro and in vivo, the pharmacokinetics of LVLX and the effectiveness and safety of it in the treatment of pulmonary tuberculosis, with ofloxacin(OFLX) as control.

Methods: The MIC and MBC of LVLX were determined by the tube doubling dilution method, and the effectiveness of the drugs were assessed by half survival time of the mice. The concentrations of LVLX and OFLX in serum were measured by HPLC. The pharmacokinetic parameters obtained were calculated. 138 newly diagnosed and retreatment pulmonary tuberculosis patients were randomly allocated to receive four chemotherapy regimens.

Results: The MIC and MBC of LVLX against Mycobacterium tuberculosis were 2 dilutions lower than that of OFLX, in a murine tuberculosis model, the antimycobacterial activity of LVLX was significant and superior to OFLX with the same dose. The concentration-time curves of LVLX and OFLX were conformed to an one-compartment model. There was no significant difference between the two formulations in the Tmax, T1/2 and 1/2 Cmax, 1/2 AUC of OFLX and LVLX. The sputum conversion rates at the end of treatments of groups I, II, III and IV were 97%, 97%, 82% and 84% respectively. X-ray resolution rates were 97%, 94%, 88% and 88% respectively. The side effects of four groups were rather low.

Conclusions: LVLX displays powerful activities against Mycobacterium tuberculosis both in vitro and in vivo, which is two times that of OFLX.LVLX and OFLX have the same good pharmacokinetic characteristics. LVLX at the dose of 300 mg/d shows the same effectiveness and fewer adverse drug reactions in comparison with OFLX at the dose of 600 mg/d in the treatment of pulmonary tuberculosis. So LVLX is a new effective and safe antituberculosis drug.