BTS publishes new guideline on non-tuberculous mycobacterial pulmonary disease
The British Thoracic Society (BTS) has published a new guideline on the management of non-tuberculous mycobacterial pulmonary disease (NTM-PD) – the first guideline on the condition since 2000.
The guideline, published as a supplement to the November 2017 issue of Thorax, is primarily aimed at healthcare professionals involved in the care of patients with NTM-PD. Since 2000, understanding of the epidemiology, microbiology and management of NTM-PD has increased significantly. Furthermore, the prevalence of NTM infections is increasing and treatment remains challenging because of a lack of clinical trial data and the problem of growing drug resistance.
The new guideline recommends using the American Thoracic Society/Infectious Diseases Society of America criteria to diagnose NTM-PD, originally published in the American Journal of Respiratory and Critical Care Medicine in 2007. The decision to start treatment should be influenced by the severity of the disease, the risk of progression and the presence of co-morbidity. If treatment needs to be initiated, the antibiotic regimen of choice depends on the species of NTM identified from respiratory samples (sputum or bronchial washings), and their drug susceptibility.
For clarithromycin-sensitive Mycobacterium avium complex (MAC) infections, rifampicin, ethambutol and clarithromycin or azithromycin should be used, in either an intermittent (three times per week) or daily oral regimen. An injectable aminoglycoside should be considered in severe disease. Clarithromycin-resistant MAC infections should be treated with rifampicin, ethambutol and isoniazid or a quinolone; an injectable aminoglycoside (amikacin or streptomycin) should also be considered.
In the case of rifampicin-sensitive Mycobacterium kansasii infection, rifampicin, ethambutol and isoniazid or a macrolide (clarithromycin or azithromycin) using a daily oral regimen is recommended. Rifampicin-resistant M. kansasii infection should be treated with a three-drug regimen guided by drug susceptibility test results.
Mycobacterium malmoense infection should be treated with rifampicin, ethambutol and a macrolide and Mycobacterium xenopi infection should be treated with a four-drug regimen comprising rifampicin, ethambutol and a macrolide, with either a quinolone or isoniazid. In severe disease, an injectable aminoglycoside should be considered.
For Mycobacterium abscessus infection, treatment is more complex, comprising an initial four-week regimen with intravenous (amikacin, tigecycline and imipenem) and oral (clarithromycin or azithromycin) antibiotics followed by a continuation phase with inhaled (amikacin) and oral antibiotics (the choice depending on drug susceptibility). Antibiotic treatment should continue for a minimum of 12 months after culture conversion for all types of NTM-PD infection.
A summary of the guidance written by the NTM guideline development group has been published in BMJ Open Respiratory Research (DOI: 10.1136/bmjresp-2017-000242), which also provides good practice points.