M. abscessus | Antibiotic regimen |
---|---|
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 |
† Due to the poorer response rates in patients with inducible or constitutive macrolide-resistant isolates and the greater efficacy of antibiotics administered through the intravenous route, extending the duration of intravenous antibiotic therapy to 3–6 months in those that can tolerate it may be the most appropriate treatment strategy in this subgroup of patients.
‡ Substitute intravenous/nebulised amikacin with an alternative antibiotic if the M. abscessus is resistant to amikacin (ie, minimum inhibitory concentration >64 mg/L or known to have a 16S rRNA gene mutation conferring constitutive amikacin resistance).
§ Start clofazimine during the initial phase of treatment if tolerated as steady-state serum concentrations may not be reached until ≥30 days of treatment.