The efficacy, safety, and feasibility of inhaled amikacin for the treatment of difficult-to-treat non-tuberculous mycobacterial lung diseases

Background

In multidrug regimens, including an intravenous aminoglycoside (e.g. amikacin [AMK]) is recommended for difficult-to-treat non-tuberculous mycobacterial (NTM) lung diseases. We aimed to evaluate the efficacy, safety, and feasibility of inhaled AMK therapy in patients with difficult-to-treat NTM lung diseases in a retrospective chart review.

Methods

The study population consisted of patients with NTM lung diseases who received combination therapy, including inhaled AMK therapy, at Keio University Hospital (Tokyo, Japan), from January 2014 through May 2016. A total of 26 cases, consisting of 23 Mycobacterium avium complex (MAC) and three Mycobacterium abscessus complex (MABC) infections cases, were included in this study. The efficacy, safety, and feasibility of inhaled AMK therapy were retrospectively investigated. The Research Ethics Committee of Keio University Hospital approved this study, and informed consent was obtained from all patients.

Results

All 26 patients were culture-positive at enrolment. Twenty-three of the 26 patients (88.5%), including 21/23 MAC patients (91.3%) and 2/3 MABC patients (66.7%), were administered inhaled AMK therapy for >3 months. The proportion of patients who had clinical symptoms, including, cough and sputum, declined after inhalation AMK therapy. Ten of the 23 patients (43.5%) who received AMK inhalation, including 8/21 MAC (38.1%) and 2/2 MABC patients (100%), showed sputum conversion, defined as at least three consecutive negative sputum cultures. Seven of the 23 patients, including, 5/21 MAC and 2/2 MABC patients, showed improvements in high-resolution computed tomography imaging of the chest. In addition, the serum AMK trough levels before the second inhalation were <1.2 μg/mL in all 26 patients, with no occurrence of severe adverse events, such as renal toxicity. One patient (3.8%) experienced auditory toxicity, in the form of tinnitus. However, this symptom was reversible, after temporary interruption of AMK, the patient was able to safely resume the therapy.

Conclusions

Inhaled AMK therapy is an effective and feasible therapy for difficult-to-treat NTM lung disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2665-5) contains supplementary material, which is available to authorized users.

Mixed Infection of Mycobacterium abscessus subsp. abscessus and Mycobacterium tuberculosis in the Lung

A mixed infection of Mycobacterium abscessus subsp. abscessus (Mab) and Mycobacterium tuberculosis (MTB) in the lung is an unusual clinical manifestation and has not yet been reported. A 61-year-old woman had been treated for Mab lung disease and concomitant pneumonia, and was diagnosed with pulmonary tuberculosis (PTB). Despite both anti-PTB and anti-Mab therapy, her entire left lung was destroyed and collapsed. She underwent left pneumonectomy and received medical therapy. We were able to successfully treat her mixed infection by pneumonectomy followed by inhaled amikacin therapy. To the best of our knowledge, thus far, this is the first description of a mixed Mab and MTB lung infection.