Treatment of Pulmonary Tuberculosis

Initial Treatment Regimen

The Centers for Disease Control and Prevention recommends a standard 6-month regimen for drug-susceptible pulmonary tuberculosis, consisting of an initial 2-month phase of isoniazid, rifampin, pyrazinamide, and ethambutol, followed by a 4-month continuation phase of isoniazid and rifampin 1
The initial phase of the standard 6-month regimen includes daily isoniazid, rifampin, pyrazinamide, and ethambutol, as recommended by the Centers for Disease Control and Prevention 1
The continuation phase of the standard 6-month regimen includes daily isoniazid and rifampin, as recommended by the European Respiratory Society 2

The European Respiratory Society recommends pyrazinamide dosing at 25 mg/kg (20-30 mg/kg) daily, or 35 mg/kg (30-40 mg/kg) 3 times weekly 2

The Centers for Disease Control and Prevention recommends drug susceptibility testing on initial isolates to guide therapy 1
The Infectious Diseases Society of America recommends an expanded regimen for suspected drug resistance, in consultation with TB experts 3, 4
The American Thoracic Society defines treatment failure as continuously or recurrently positive cultures after 4 months of appropriate therapy, and recommends against adding a single drug to a failing regimen 7

The Centers for Disease Control and Prevention recommends extending the continuation phase to 7 months (total 9 months) for cavitary pulmonary TB with positive cultures after 2 months of therapy 1
The American Thoracic Society recommends extending treatment to 9-12 months for TB meningitis 5

The Infectious Diseases Society of America reports that most patients (90-95%) will be culture-negative after 3 months of appropriate therapy, and recommends evaluating patients with persistently positive cultures for nonadherence, unrecognized drug resistance, malabsorption issues, and diabetes mellitus 3, 6

The American Thoracic Society recommends adding at least two, preferably three, new drugs to which susceptibility can be inferred for treatment failure, and considering adding a fluoroquinolone, an injectable agent, and an additional oral agent 7
The American Thoracic Society recommends obtaining cultures for drug susceptibility testing and restarting the standard four-drug regimen for relapse after completing treatment, if previously treated with DOT and drug-susceptible TB 7