Comprehensive treatment of extensively drug-resistant tuberculosis

Abstract

Background: Extensively drug-resistant tuberculosis has been reported in 45 countries, including countries with limited resources and a high burden of tuberculosis. We describe the management of extensively drug-resistant tuberculosis and treatment outcomes among patients who were referred for individualized outpatient therapy in Peru.

Methods: A total of 810 patients were referred for free individualized therapy, including drug treatment, resective surgery, adverse-event management, and nutritional and psychosocial support. We tested isolates from 651 patients for extensively drug-resistant tuberculosis and developed regimens that included five or more drugs to which the infecting isolate was not resistant.

Results: Of the 651 patients tested, 48 (7.4%) had extensively drug-resistant tuberculosis; the remaining 603 patients had multidrug-resistant tuberculosis. The patients with extensively drug-resistant tuberculosis had undergone more treatment than the other patients (mean [+/-SD] number of regimens, 4.2+/-1.9 vs. 3.2+/-1.6; P<0.001) and had isolates that were resistant to more drugs (number of drugs, 8.4+/-1.1 vs. 5.3+/-1.5; P<0.001). None of the patients with extensively drug-resistant tuberculosis were coinfected with the human immunodeficiency virus (HIV). Patients with extensively drug-resistant tuberculosis received daily, supervised therapy with an average of 5.3+/-1.3 drugs, including cycloserine, an injectable drug, and a fluoroquinolone. Twenty-nine of these patients (60.4%) completed treatment or were cured, as compared with 400 patients (66.3%) with multidrug-resistant tuberculosis (P=0.36).

Conclusions: Extensively drug-resistant tuberculosis can be cured in HIV-negative patients through outpatient treatment, even in those who have received multiple prior courses of therapy for tuberculosis.

Figure 1. Use of Antituberculosis Agents in 48 Individualized Treatment Regimens for MDR Tuberculosis, Drug-Susceptibility Testing, and Prior Exposure to a Particular Agent

Some susceptibility testing was performed for these agents. Asterisks indicate that some testing was performed for these agents. However, because of the relative infrequency of testing, as well as the lack of standardization or confirmed clinical relevance of tests for these drugs, clinicians relied less on these results than on those for other drugs.