INTRODUCTION: Traditionally, Mycobacterium abscessus pulmonary disease has poor long term response to current antibiotic regimens. The data regarding the clinical efficacy of linezolid and aerosolized amikacin in M. abscessus pulmonary disease is limited.
CASE PRESENTATION: A 52 year-old Caucasian female presented in 2004 with scant hemoptysis and intermittent night sweats. Her past medical history was unremarkable. She denied history of pneumonias. She did not smoke tobacco. She worked as a middle school secretary. Computed tomographic (CT) evaluation of the chest showed significant bronchiectasis in the right middle lobe with irregular opacities throughout the right upper lobe and right lower lobe. She was treated empirically with levofloxacin for recurrent episodes of infection with a presumed response. In 2007, she had more severe hemoptysis with several teaspoons of bright red blood that woke her up from sleep at night. M. chelonae and M. abscessus were identified in her sputum and she was started on clarithromycin combined with ciprofloxacin. In 2008, pulmonary function tests showed evidence of decreasing diffusing capacity. Chest CT showed interval increase in the nodular densities primarily in the right middle lobe and many were cavitating. She required hospitalization in 2009 for increasing hemoptysis and underwent IR embolization of branches of the right bronchial artery and right internal mammary artery. Nebulized amikacin 250 mg daily was started along with linezolid 600 mg daily. After 6 months of moxifloxacin, clarithromycin, nebulized amikacin, and linezolid, chest CT in late 2009 showed improvement and there was no further hemoptysis.
DISCUSSIONS: Intermittent courses of parenteral therapy combined with and followed by an oral macrolide, aerosolized amikacin, and linezolid may be used to suppress infection and control disease progression of M. abscessus pulmonary disease.(1) Cost and side effects may limit the feasibility of prolonged treatment with parenteral antibiotic therapy. Aminoglycosides exhibit significant concentration-dependent bactericidal activity against nontuberculous mycobacteria. Extended parenteral therapy with aminoglycosides has been avoided due to the substantial risks of nephrotoxicity, ototoxicity, and vestibular toxicity. Aerosolized antibiotic delivery offers the potential advantage of achieving high drug concentrations in the lung with low systemic absorption and diminished risk of systemic toxicities. Aerosolized antibiotics have been used with notable success in the treatment of chronic Pseudomonas aeruginosa infection in patients with cystic fibrosis. In an observational case series, six HIV-negative patients with Mycobacterium avium intracellulare pulmonary infections who had failed standard therapy were administered aerosolized amikacin at 15 mg/kg daily in addition to standard multi-drug macrolide-based oral therapy. Five responded to therapy and achieved symptomatic improvement. Four were sputum culture negative after 6 months of therapy.(2) Approximately 50% of M. abscessus isolates are susceptible or exhibit intermediate susceptibility in vitro to the oxazolidinone linezolid. A small number of patients with M. abscessus lung disease have been treated with linezolid and a companion drug, usually a macrolide, with varied results. Impediments to long-term use of linezolid include the cost and potential side effects of chronic therapy which include peripheral neuropathy and anemia. Once daily dosing of linezolid 600mg instead of the traditional twice daily dosing is currently used by some to treat mycobacterial disease with seemingly fewer side effects and retained antimycobacterial activity.
CONCLUSION: Preliminary case series suggest that nonparenteral agents including oral macrolides, aerosolized amikacin, and linezolid may be effective for the treatment of M. abscessus pulmonary disease.
DISCLOSURE: Richard Lee, No Financial Disclosure Information; No Product/Research Disclosure Information