Daily 300 mg dose of linezolid for multidrug-resistant and extensively drug-resistant tuberculosis: updated analysis of 51 patients

Linezolid may be an effective treatment for multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB). The objective was to evaluate the efficacy, tolerability and adverse events of a 300 mg daily dose of linezolid in the treatment of MDR/XDR-TB. We retrospectively reviewed the medical records of 51 MDR-TB patients, including 26 patients (51%) with XDR-TB, to evaluate the safety, tolerability and efficacy of therapy with 300 mg/day linezolid. All patients had failed previous treatments with second-line anti-TB drugs. Patients were treated with linezolid for a median of 413 days (IQR 237-622 days). Favourable treatment outcome (treatment success or still on treatment after culture conversion) was achieved in 40 patients (78%) with culture conversion at a median of 55 days (IQR 41-91 days) from the start of linezolid therapy. Eleven patients (22%) had unfavourable outcomes (treatment failure or death) and 14 (27%) discontinued treatment due to neurotoxicity (peripheral or optic neuropathy) after a median of 278 days (IQR 174-412 days). Our findings suggest that linezolid at a daily dose of 300 mg is effective against intractable MDR/XDR-TB, and may be associated with fewer neuropathic side effects than a daily dose of 600 or 1200 mg.