[Role of new quinolones in the treatment of mycobacteriosis].

New quinolones (NQs) have acquired potent antimicrobial activity against gram-positive cocci and penetrate well into organs when compared with old quinolones. Their indications were extended to the treatment of respiratory infection caused by gram-negative and gram-positive bacteria, and their possibility of an indication for the treatment of mycobacteriosis has been considered. Mycobacteriosis, against which NQs are expected to be effective, includes tuberculosis, which involves a problem of multiple-drug resistant bacteria, and atypical mycobacteriosis, for which there are few remedies. Since, there has been no established evaluation of NQs against mycobacteriosis, the purpose of the present evening symposium was to evaluate the role of NQs at present in the treatment of mycobacteriosis, as well as to present future prospects. Four speakers made presentations. Dr. Chiaki Sano reported that STFX, GFLX, MXFX, and SPFX had a potent antibacterial activity against various acid-fast bacteria and were particularly effective against M. tuberculosis, M. kansasii, and M. fortuitum. Among these drugs, MXFX had a greater therapeutic effect in experimental mice model of a tuberculosis than SM when used concomitantly with INH + RPT. These results suggested that MXFX might become one of the first-line drugs, taking the place of SM. However, OFLX, SPFX, and STFX are not effective against MAC. Only MXFX exhibited a significant therapeutic effect when administered alone and potent therapeutic effect when used concomitantly with EB, in experimental mice model of MAC infection. These results suggested that 8-methoxy quinolone might be effective. Dr. Yuka Sasaki reported the results of a questionnaire survey among national sanatoriums, as well as the current status of administration of NQs for the treatment of pulmonary tuberculosis based on the results of her study. The ATS recommended in 2002 that LVFX, MXFX, and GFLX be second-line drugs, which should be used alternatively only when first-line drugs cannot be used due to drug-resistant M. tuberculosis or adverse reactions. She reported that LVFX, MXFX, and GFLX were used in a similar manner also in Japan and that they achieved therapeutic results equivalent to those by first-line drugs. She stated that there were some urgent problems, for example, these drugs are not listed in the Tuberculosis Control Law of Japan or in health insurance, and no testing system for sensitivity to NQs has been established. Dr. Atsuyuki Kurashima reported the results of a study conducted in other countries and his study on atypical acid-fast bacteria. He indicated the position of NQs in the treatment of pulmonary atypical mycobacteriosis. However, the significance of concomitant use of CPFX with RFP + EB in the treatment of MAC disease associated with AIDS has already been recognized. He was of the opinion that atypical acid-fast bacteria against which NQs were useful were M. kansasii and M. fortuitum alone at present and that NQs had a very limited effect in the treatment of pulmonary MAC infection, although there were only an insufficient number of studies on pulmonary MAC disease. Dr. Koichi Wada reported on the advisability of administration of NQs in the treatment of mycobacteriosis as a whole and prospects for NQs. His conclusion was similar to those by the two former speakers: he stated that NQs are important for the treatment of tuberculosis as alternative drugs and that they should be used in sufficient doses when first-line drugs could not be used due to drug resistance or adverse reactions. He also stated that use of NQs, including duration of administration, should be discussed after the testing method for drug sensitivity has been established and that long-term use of NQs should be avoided in the treatment of atypical mycobacteriosis at present, although significant results have not been obtained in atypical acid-fast bacteria, mainly MAC. In the last part of the symposium, an active discussion was held. Many opinions similar to those of the speakers were expressed also from the floor. Lastly, President Dr. Matsushima summarized the role of NQs in the treatment of mycobacteriosis at present and future prospects for NQs and confirmed the significance of having held the present symposium.