STANDARD TREATMENT — Patients with drugsusceptible tuberculosis have typically been treated with rifampin, isoniazid, pyrazinamide, and ethambutol during an initial 8-week intensive phase, and then with rifampin and isoniazid during an 18-week continuation phase. Once-daily treatment is preferred, but twice- or three-times-weekly dosing can be used as an alternative in patients who are HIV-negative and do not have smear-positive or cavitary disease. Directly observed therapy should be used to ensure treatment adherence.1

THE CLINICAL TRIAL — Study 31/A5349 was a randomized, open-label trial in which 2516 patients ≥12 years old with pulmonary tuberculosis were randomized to receive 6 months of standard once-daily treatment or one of two 4-month treatment regimens using high-dose rifapentine, isoniazid, pyrazinamide, and either moxifloxacin or ethambutol. The 4-month regimen that included moxifloxacin was noninferior to standard treatment for the primary endpoint of disease-free survival at 12 months (88% vs 90%) and similar to standard treatment in safety and tolerability. The 4-month regimen with ethambutol did not meet the prespecified criteria for noninferiority compared to standard treatment.2

CONCLUSION — The positive results with the 4-month regimen have been recognized by the CDC and the WHO as an important development in the effort to improve treatment of tuberculosis.3,4 Shortening the required duration of antimicrobial therapy may increase treatment adherence, which could theoretically decrease disease prevalence and the risk for development of drug resistance.