Moxifloxacin (BAY12-8039) HCl

Moxifloxacin exerts its effects by trapping a DNA drug enzyme complex and specifically inhibiting ATP-dependent enzymes topoisomerase II (DNA gyrase) and topoisomerase IV. Moxifloxacin shows in-vitro potency against M. tuberculosis H37Rv with MIC of 0.177 μg/mL. Moxifloxacin has broad Grampositive and Gram-negative activity. Moxifloxacin shows in vitro and clinical efficacy against Staphylococcus aureus, Streptococcus pneumoniae, Str. pyogenes, Haemophilus influenzae, H. parainfluenzae, Klebsiella pneumoniae, Moraxella catarrhalis, Chlamydia pneumoniae and Mycoplasma pneumoniae. Moxifloxacin has activity against mycobacteria in addition to M. tuberculosis; Moxifloxacin is more active against M. kansasii than M. avium complex: specifically MIC90 for M. avium > M. intracellulare > M. kansasii at 4, 2 and 2 μg/mL, respectively. MIC90 for M. chelonae > M. fortuitum at 16 and 0.5 μg/mL, respectively. ^[1]

Moxifloxacin combined with RIF/pyrazinamide (PZA) reduces treatment time by up to 2 months compared to regimens with isoniazid (INH)/RIF/PZA in a mouse model designed to mimic human disease. Similar results with a stable cure are reached after 4 months in mice treated twice weekly with RIF/Moxifloxacin/PZA compared to cure in 6 months when daily treated with RIF/INH/PZA. 100 mg/kg Moxifloxacin in mice gives activity comparable to INH; increased dose in mice to 400 mg/kg Moxifloxacin daily results in spleen CFU counts lower than for INH 25 mg/kg although the differences are not statistically significant. AUC/MIC ratio correlates best with in-vivo efficacy for the fluoroquinolones in a mouse model of tuberculosis. ^[1]