^a All drugs should be given daily. Recommended daily dosages for adults: isoniazid, 5 mg/kg, max 300 mg; rifampin, 10 mg/kg, max 600 mg; pyrazinamide, 25 mg/kg, max 2 g; and ethambutol, 15 mg/kg.

^bStreptomycin was used in the past in place of ethambutol but is no longer considered a first-line drug.

^c A clinical trial showed that HIV-negative pts with noncavitary pulmonary tuberculosis who have negative sputum AFB smears after the initial phase of treatment can be given once-weekly rifapentine/isoniazid in the continuation phase. However, this regimen is rarely used.

^d The American Thoracic Society, the Centers for Disease Control and Prevention, and the Infectious Diseases Society of America suggest that a 2-month continuation phase could be used in HIV-seronegative pts with sputum smear-negative and culture-negative TB.

^e The 6-month regimen with pyrazinamide can probably be used safely during pregnancy and is recommended by the WHO and the International Union against Tuberculosis and Lung Disease. If pyrazinamide is not included in the initial treatment regimen, the minimal duration of therapy is 9 months.

^f The availability of rapid molecular methods to identify drug resistance allows initiation of a proper regimen at the start of treatment.

Abbreviations: E, ethambutol; H, isoniazid; MDR-TB, multidrug-resistant tuberculosis; Q, a quinolone antibiotic; R, rifampin; WHO, World Health Organization; XDR-TB, extensively drug-resistant tuberculosis; Z, pyrazinamide.