Antibacterial Activity and Clinical Efficacy of Sparfloxacin in Mycobacterium avium-intracellulare Complex Infection

Combined administration of rifampicin, ethambutol, and clarithromycin for the treatment of tenosynovitis of the hand caused by Mycobacterium avium complex: Case series and literature review

ABSTRACT

We report the clinical results and problems of combined administration of rifampicin, ethambutol, and clarithromycin (REC) for the treatment of Mycobacterium avium complex (MAC) infection of the hand (hand MAC).Participants included 7 patients with hand MAC. After resection of the infected lesion, REC was prescribed for 12 months. For these patients, the site of infection, clinical course after initiation of REC, adverse drug effects (ADEs), and incidence of recurrence were evaluated.Sites of infection were the flexor tenosynovium in 5 patients, extensor tenosynovium in 1 patient, and both flexor and extensor tenosynovium in 1 patient. ADEs of REC occurred in 5 patients, and included visual disturbance caused by ethambutol in 2 patients, liver function abnormality caused by rifampicin in 2 patients, and fever with diarrhea caused by rifampicin in 1 patient. For 2 of these 5 patients, desensitization therapy was applied and REC was able to be reinstated. In the remaining 3 patients, the causative drugs were discontinued and levofloxacin, a new quinolone, was administered. Complete healing was achieved in 5 patients, and recurrence was observed in 2 patients. These 2 patients with recurrence included 1 patient in whom REC was completed and 1 patient in whom REC therapy was modified due to ADE.REC provided relatively good clinical results as a treatment for hand MAC. However, recurrences were observed even after the completion of REC and the use of an alternative drug. Optimal duration of REC and appropriate alternative drugs need to be identified in the future.

Relationship between clinical efficacy for pulmonary MAC and drug-sensitivity test for isolated MAC in a recent 6-year period

There are a few recent reports about the relationship between the clinical effect and drug-sensitivity test. We investigated the relationship between the clinical efficacy of treatment for pulmonary Mycobacterium avium complex (MAC) and drug-sensitivity test for isolated MAC by comparison between data from 2005 to 2007 and from 2008 to 2010. We studied 60 patients who satisfied diagnostic criteria of nontuberculous mycobacterial infection established by the American Thoracic Society in 2007 and who received combination therapy using rifampicin (RFP), ethambutol (EB), streptomycin (SM), and clarithromycin (CAM). Average CAM dosage was increased from the early (517 mg/day) to the later (800 mg/day) period. Sputum conversion rate increased from 63% in the early period to 83% in the later period. Clinical improvement also increased from 38% in the early period to 53% in the later period. The causative microorganisms isolated were M. avium in 35 patients and M. intracellulare in 25. In both periods, isolated MAC strains showed excellent minimum inhibitory concentration (MIC) for CAM. Regarding the relationship between clinical efficacy and MICs of RFP, EB, CAM, and SM, most patients with good clinical effects showed low MIC for CAM in both periods. Good clinical efficacy, including the sputum conversion rate, was obtained with an increased dose of CAM in the later period. We speculate that the increased dose of CAM influenced the good clinical effect in both periods.

The clinical efficacy and safety of a fluoroquinolone-containing regimen for pulmonary MAC disease

Despite recent advances in chemotherapy, the treatment of pulmonary Mycobacterium avium complex (MAC) disease remains unsatisfactory. Judging from its MIC, fluoroquinolones including gatifloxacin (GFLX) are expected to demonstrate efficacy against MAC disease. However, there have been few clinical studies using fluoroquinolones. Therefore, a prospective study to evaluate the clinical efficacy and safety of a fluoroquinolone-containing regimen for the treatment of pulmonary MAC disease was conducted. In this trial, patients with pulmonary MAC disease received protocol-guided combined chemotherapy with rifampin (RFP) and ethambutol (EB) plus either GFLX or clarithromycin (CAM). Adult patients who fulfilled the criteria of the ATS definition of pulmonary MAC disease were enrolled in this study. The patients provided their informed consent, and treatments were administered for 1 year. Of 27 patients enrolled from three facilities, 14 patients were treated with the CAM-containing regimen and 13 patients were treated with the GFLX-containing regime. Four patients did not complete the 1-year treatment because of adverse events. Nine patients (64.3%) in the CAM group and 11 patients (84.6%) in the GFLX group achieved eradication of pathogens. Adverse events were observed more frequently in the GFLX group than in the CAM group. However, there were no severe adverse events in either group. The long-term results showed a similar relapse rate between the CAM and GFLX groups. The fluoroquinolone-containing regimen demonstrated both high efficacy and relative safety for pulmonary MAC disease that was similar to that of the CAM-containing regimen, which is considered to be the standard regimen.

Relationship between clinical efficacy of treatment of pulmonary Mycobacterium avium complex disease and drug-sensitivity testing of Mycobacterium avium complex isolates

We prospectively investigated the relationship between the clinical efficacy of treatment of pulmonary Mycobacterium avium complex (MAC) disease and drug-sensitivity testing of MAC isolates for antituberculous drugs, new quinolone antibiotics, and clarithromycin (CAM). Fifty-two patients who satisfied the diagnostic criteria of the American Thoracic Society (ATS) and who received treatment between April 1998 and December 2005, using combined therapy of rifampicin (RFP), ethambutol (EB), streptomycin (SM), and CAM, were enrolled in this study. The causative microorganisms isolated were Mycobacterium avium in 30 patients and M. intracellulare in 22 patients. Although separation of the two strains showed drug sensitivity testing to have slightly better minimal inhibitory concentrations (MIC) for M. intracellulare than for M. avium, there were no significant differences in the sputum eradication rate or clinical improvement between the two strains. The MICs of various antibiotics for the isolated MAC strains were as follows: RFP, 0.125-8 microg/ml; CAM, 0.25-16 microg/ml; SM, 2-128< or =microg/ml; EB, 128< or = microg/ml; levofloxacin (LVFX), 1-32 microg/ml; sparfloxacin (SPFX), 0.5-16 microg/ml; and gatifloxacin (GFLX), 0.25-8 microg/ml. The isolated MAC strains showed the same excellent drug sensitivity test results for RFP, new quinolones, and CAM, but they showed resistant drug-sensitivity results for EB and SM. Regarding the relationship between clinical efficacy and the MICs of RFP, EB, CAM, and SM, there was a good relationship only for CAM. Although the ATS has not yet recommended routine drug susceptibility testing of CAM, we believe that drug susceptibility testing of CAM should be performed before the initial treatment is undertaken for pulmonary MAC disease.