In vitro activity of four fluoroquinolones against Mycobacterium tuberculosis

In vitro activity of moxifloxacin, levofloxacin, gatifloxacin and linezolid against Mycobacterium tuberculosis

The in vitro activity of moxifloxacin, gatifloxacin, levofloxacin and linezolid was evaluated against 234 strains of Mycobacterium tuberculosis isolated in the Southeast of Spain. All drugs tested showed good activity, with an MIC(90) of less than 1 mg/l, and were active against isociacide and rifampicin resistant strains. Three strains were resistant to isoniazid and to the fluoroquinolones, which suggested the existence of mechanisms of resistance not yet described. These new compounds may prove to be therapeutic alternatives for treatment of multi-resistant tuberculosis and further studies should be done to demonstrate their true usefulness.

In vitro and in vivo activities of gatifloxacin against Mycobacterium tuberculosis

Gatifloxacin (GAT) and moxifloxacin (MXF) were evaluated in vitro to determine their activities against Mycobacterium tuberculosis. GAT was subsequently compared in a dose range study to isoniazid (INH) in a murine tuberculosis model. GAT was somewhat less active than INH. GAT and MXF were evaluated in mice infected with M. tuberculosis and were found to have similar activities. GAT was studied alone and in combination with ethambutol, ethionamide (ETA), and pyrazinamide (PZA) and compared to INH and rifampin (RIF). GAT appears to have sufficient activity alone and in combination with ETA with or without PZA to merit evaluation for treatment of tuberculosis.

Fluoroquinolones and tuberculosis

Tuberculosis (TB) remains one of the main causes of morbidity worldwide, and the emergence of multi-drug resistant (MDR) Mycobacterium tuberculosis strains in some parts of the world has become a major concern. The decrease in activity of the major anti-TB drugs, such as isoniazid and rifampicin, is an important threat and alternative therapies are urgently required. The anti-TB activity of the fluoroquinolones has been under investigation since the 1980s. Many are active in vitro but only a few, including ofloxacin, ciprofloxacin, sparfloxacin, levofloxacin and lomefloxacin, have been clinically tested. Fluoroquinolones can be used in co-therapy with the available anti-TB drugs. However, the choice of fluoroquinolone should be based not only on the in vitro activity, but also on the long-term tolerance. Fluoroquinolones are novel anti-TB drugs to be used when a patient is infected with a MDR-TB strain.

[Efficacy of the sparfloxacin-ethambutol combination in a case of cerebral tuberculosis]

INTRODUCTION

Treatment of cerebral tuberculomas demands the combination of rifampicin, isoniazid, pyrazinamide and ethambutol. The place of fluoroquinolones remains to be defined.

EXEGESIS

A 36-year-old woman presented with a cerebral tuberculoma. Treatment with an antituberculous quadritherapy regimen was begun, but because of serious side effects, isoniazid and rifampicin weren't withdrawn during the fourth month. Sparfloxacin and ethambutol biotherapy was then started and continued for 12 months, which led to the disappearance of the cerebral lesion.

CONCLUSION

Our observation proves that sparfloxacin is an alternative for cerebral tuberculoma treatment in case of intolerance or resistance to first-line antituberculosis drugs.