Tuberculosis re-treatment after exclusion of rifampicin resistance

We agree with Falzon et al. [1] that treatment of isoniazid-resistant tuberculosis (TB) is an important issue. The first-line re-treatment regimen for previously treated TB patients, which was known as the category II regimen, comprised 8 months of isoniazid, rifampicin and ethambutol supplemented by streptomycin for the initial 2 months, and pyrazinamide for the initial 3 months (2SHRZE/HRZE/5HRE). It was introduced in the collaborative programme of the International Union Against Tuberculosis and Lung Disease in which the first-line initial regimen for new TB patients was an 8-month regimen comprising 2 months of isoniazid, rifampicin, pyrazinamide and streptomycin, followed by 6 months of isoniazid and thioacetazone (2HRZS/6HT) [2]. At that time, the prevalence of multidrug-resistant (MDR)-TB among previously treated TB cases was relatively low and the challenge was mainly isoniazid resistance [3]. The category II regimen was designed to overcome isoniazid resistance and to reduce the risk of acquired resistance to rifampicin. It performed fairly well in settings where resistance to isoniazid predominated among previously treated TB patients [4]. However, with the wide use of a 6-month regimen including rifampicin throughout the whole treatment course (2HRZE/4HR) for new TB patients (category I regimen), the prevalence of rifampicin resistance among previously treated TB patients increased substantially [5], rendering the category II regimen ineffe...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Respiratory infections and tuberculosis Original Articles: Correspondence Source Type: research