Mycobacterium abscessus
Suggested antibiotic regimens refer to the BTS guidelines for adults with Mycobacterium abscessus pulmonary disease. The evidence base is grade D and treatment varies between units and countries. Please refer to the full guidelines (link below). A few suggestions from the guidelines are shown below.
Can nebulised amikacin be used instead of intravenous amikacin?
Nebulised amikacin may be considered in place of intravenous amikacin when intravenous administration is impractical, contraindicated or longer term treatment with an aminoglycoside is required..
What if there is amikacin resistance?
If MIC >64 mg/L or the isolate is known to have a 16S rRNA gene mutation conferring constitutive amikacin resistance then intravenous/nebulised amikacin should be substituted with an alternative intravenous/oral antibiotic.
What if macrolide resistant?
Patients with M. abscessus complex isolates that demonstrate constitutive macrolide resistance (Functional erm(41) gene, 23S ribosomal RNA point mutation), the continuation phase antibiotic regimen should include nebulised amikacin in combination with two to four of the following oral antibiotics guided by drug susceptibility and patient tolerance: clofazimine, linezolid, minocycline or doxycycline, moxifloxacin or ciprofloxacin, and co-trimoxazole.
How long should you continue treatment?
Antibiotic treatment for M. abscessus pulmonary disease should continue for a minimum of 12 months after culture conversion.
Clarithromycin sensitive isolates or inducible macrolide-resistant isolates
Initial phase: ≥1 month
Intravenous amikacin 15 mg/kg daily or 3× per week
and intravenous tigecycline 50 mg twice daily
and where tolerated intravenous imipenem 1 g twice daily
and where tolerated oral clarithromycin 500 mg twice daily or oral azithromycin 250–500 mg daily
Continuation phase:
nebulised amikacin
and oral clarithromycin 500 mg twice daily or azithromycin 250–500 mg daily
and 1–3 of the following antibiotics guided by drug susceptibility results and patient tolerance:
oral clofazimine 50–100 mg daily
oral linezolid 600 mg daily or twice daily
oral minocycline 100 mg twice daily
oral moxifloxacin 400 mg daily
oral co-trimoxazole 960 mg twice daily
Constitutive macrolide-resistant isolates
initial phase:
≥1 month intravenous amikacin 15 mg/kg daily or 3× per week
and intravenous tigecycline 50 mg twice daily
and where tolerated intravenous imipenem 1 g twice daily
Continuation phase:
nebulised amikacin
and 2–4 of the following antibiotics guided by drug susceptibility results and patient tolerance:
oral clofazimine 50–100 mg daily
oral linezolid 600 mg daily or twice daily
oral minocycline 100 mg twice daily
oral moxifloxacin 400 mg daily
oral co-trimoxazole 960 mg twice daily