Evaluation of tuberculosis treatment including levofloxacin (LVFX) in cases who could not continue standard regimen

OBJECTIVE: The purpose of this study was to evaluate tuberculosis treatment including levofloxacin (LVFX) and to investigate the effectiveness of changing drug regimens at our hospital. SUBJECTS AND METHODS: A retrospective study was conducted on 331 patients with tuberculosis admitted to Tokyo National Hospital in 2005. Out of these 331 patients, LVFX was used in 48 (14.5%), 41 of which were initial-treatment cases. We studied why and how LVFX was used and compared bacteriological negative conversion rates between the initial-treatment cases in which the initial standard regimen was changed to regimens including LVFX, and those in which the initial standard regimen was either maintained throughout or modified with drugs other than LVFX. Sputum cultures were examined with Mycobacteria Growth Indicator Tube System (BACTEC MGIT 960). RESULTS: LVFX was used in 41 (13.6%) of 302 initial-treatment cases and in 7 (24.1%) of 29 retreatment cases. Out of the 269 initial-treatment cases starting with the standard regimen, LVFX was later used in 26 cases (9.7%). The reasons for using LVFX were adverse reaction to antituberculosis drugs in 23 cases (88.5%) and resistance to antituberculosis drugs in 3 cases (11.5%). We investigated the bacteriological conversion rate in 228 patients who could be followed up for more than five months. The conversion rates in 105 cases under the standard regimen including PZA (PZA+) were 92.4% in three months, 98.1% in four months, and 100% in five months. The rates in 56 cases under the standard regimen without PZA (PZA-) were 92.9 %, 98.2% and 100%,respectively. The rates of 22 cases under the initial regimen modified with LVFX (LVFX +) were 68.2 %, 95.5% and 100%, respectively. In 45 cases under the initial regimen modified with drugs other than LVFX (LVFX-), the rates were 80.0%, 97.8% and 100%, respectively. CONCLUSION: This study showed that LVFX was an effective drug in terms of the bacteriological conversion rate, without adverse reaction. LVFX is not approved as an antituberculosis drug in Japan, but it is often used in cases of MDR-TB or in situations in which the patients cannot continue treatment with the standard regimen. We hope that LVFX will be approved as an antituberculosis drug as soon as possible in Japan.