Isoniazid resistance is reported throughout the world, and has increased in the United Kingdom (UK) from 5.6% in 1994 to 7.7% in 2006. Few controlled trial data on the treatment of isoniazid resistance are available. If isoniazid resistance is known before treatment commencement, then a supervised regimen of rifampicin (R) and ethambutol (E) for nine months, supplemented by two months initial pyrazinamide (Z) and streptomycin (S), 2RSZE/7RE, had over a 95% cure rate. Case series, but not trials, have been described for isoniazid resistance diagnosed after treatment has commenced using various regimens. Although an analysis of the results of the treatment of isoniazid resistance in the various British Medical Research Council trials suggested that isoniazid resistant TB responded satisfactorily to standard 6-month short-course chemotherapy, developed countries recommend stopping the isoniazid once resistance to it is diagnosed.
Last date updated on July, 2014