Clinical efficacy and safety of multidrug therapy including thrice weekly intravenous amikacin administration for Mycobacterium abscessus pulmonary disease in outpatient settings: A case series

Background: Mycobacterium abscessus (M. abscessus) pulmonary disease is a refractory chronic infectious disease. Options for treating M. abscessus pulmonary disease are limited, especially in outpatient settings. Among parenteral antibiotics against M. abscessus, intravenous amikacin (AMK) is expected to be an effective outpatient antimicrobial therapy. This study evaluated the clinical efficacy and safety of intravenous AMK therapy in outpatients with M. abscessus pulmonary disease. Methods: This retrospective chart review of cases of M. abscessus pulmonary disease evaluated patient background data, AMK dosage and duration, sputum conversion, clinical symptoms radiological findings, and adverse events. M. massiliense was excluded on the basis of multiplex PCR assay. Results: Thirteen patients (2 men and 11 women) with M. abscessus pulmonary disease were enrolled at 2 hospitals. The median age at the initiation of intravenous AMK treatment was 65 years (range: 50-86 years). Patients received a median AMK dose of 12.5 mg/kg (range: 8.3-16.2 mg/kg) for a median duration of 4 months (range: 3-9 months). The addition of intravenous AMK led to sputum conversion in 10 of 13 patients, and 8 patients continued to have negative sputum status 1 year after treatment. Approximately half of the patients showed improvement on chest high-resolution computed tomography. There were no severe adverse events such as ototoxicity, vestibular toxicity, and renal toxicity. Conclusions: Thrice weekly intravenous AMK administration in outpatient settings is effective and safe for patients with M. abscessus pulmonary disease.