A prospective open study to determine the efficacy and tolerability of oral linezolid 600mg./day for the treatment of 40 patients with nontuberculous mycobacterial diseases will be conducted at Siriraj Hospital, Mahidol University, Bangkok, Thailand.

This will be an open label clinical study of oral linezolid combination with another oral antimycobacterial drug as the maintenance treatment of nontuberculous mycobacterial diseases in adult.

The eligible patients will be treated and monitored for the efficacy and safety every 6 weeks until 6 months then every 3 months for a total duration of 18 months.

Inclusion Criteria:

• Diagnosis of non-tuberculous mycobacterial (NTM) diseases
• Active or stable diseases receiving either parenteral or oral antimycobacterial treatment
• Require at least more than 6 months of treatment from enrollment

Exclusion Criteria:

• Stable NTM diseases with a plan to discontinue treatment within 3 months
• History of allergy to linezolid
• Hemoglobin < 7 g/dl) or total white blood count < 3,000 /cu.mm. or thrombocytopenia < 50,000 cells/cu.mm.
• Concomitant uses of serotoninergic drugs (SSRIs) or Monoamine oxidase inhibitor (MAOIs) within 30 days prior to enrollment
• Abnormal neurological findings such as numbness, abnormal vision etc.