We will enroll 24-36 patients, 8-12 at each dose of 600, 900 and 1200 mg rifapentine Admissions for pharmacokinetic studies will take place during the continuation phase of tuberculosis therapy. Patients participating in a double-blinded trial of the tolerability and safety of higher doses of rifapentine during continuation phase therapy and consenting to participate in the pharmacokinetic study may be admitted to a Clinical Research Center (CRC) to allow for frequent blood sampling over a 24-hour period. Otherwise, patients will be evaluated in the clinic.