Treatment Outcomes of Patients With Multidrug-Resistant and Extensively Drug-Resistant Tuberculosis According to Drug Susceptibility Testing to First- and Second-line Drugs: An Individual Patient Data Meta-analysis

Abstract

DST for ethambutol, pyrazinamide, and second-line tuberculosis drugs appears to provide clinically useful information to guide selection of treatment regimens for MDR and XDR tuberculosis.

Determination of MIC Breakpoints for Second-Line Drugs Associated with Clinical Outcomes in Multidrug-Resistant Tuberculosis Treatment in China

“…2). This relationship has been shown in previous studies (2,22). In addition, there were no differences in important variables related to treatment outcome, except for the higher frequency of pulmonary cavities and severe pulmonary disease on CXR in the group of patients with MICs above the CART-derived breakpoints.…”

“…In a univariate analysis, we found that prior TB treatment was significantly associated with both the failure to convert on sputum culture by 4 months of treatment and poor treatment outcome, highlighting the importance of appropriate treatment for MDR-TB. The relationship between the previous TB treatment and poor treatment outcome had been confirmed already in a meta-analysis (2). Additionally, indicators of disease severity, such as cavity and severe pulmonary disease on CXR, increase the risk of poor treatment outcome by inadequate penetration of the drug into the most diseased tissue due to the damaged lung parenchyma (30)(31)(32)(33).…”

“…Although drug resistance requires modification of the drug regimen and is known to be associated with worse treatment outcomes, other factors, such as nonadherence, medical comorbidities, and pharmacokinetic variability, also contribute to poor outcome of tuberculosis treatment (2,(27)(28)(29). Several factors showed at least a weak association with early sputum culture conversion or treatment outcome.…”

“…The emergence of multidrug-resistant (MDR) M. tuberculosis strains has complicated treatment and is associated with increased treatment failure (2). A reduction in the efficacy of second-line drugs (SLDs) against MDR tuberculosis (MDR-TB) strains with resistance to SLDs has been described in observational studies (2,3). Subtle changes in drug susceptibility may be predictive of clinical failures, especially when the drug susceptibility testing (DST) result is at the borderline of the susceptibility range.…”

Prevalence of Mycobacterium tuberculosis resistance to quinolones and injectables in Colombia, 2012-2013

“…Estos datos evidencian la necesidad de mejorar el acceso de los pacientes a dichas pruebas, en especial, porque proporcionan información clínicamente útil para orientar la selección de los esquemas de tratamiento, aunque las posibilidades de curación disminuyen con la presencia de formas de resistencia más graves (21,22). En Colombia, la curación de los casos multirresistentes no supera el 50 %, pero no se sabe si ello está relacionado con la ausencia de pruebas de sensibilidad o con la efectividad de los esquemas de tratamiento (4).…”