This is a one-period, non-blinded, multi-center pharmacokinetic substudy of rifapentine and rifampin in patients with tuberculosis enrolled in Tuberculosis Trials Consortium (TBTC) Study 29. This PK substudy will use a convenience sample, i.e. be restricted to TBTC sites having logistical capacity for intensive pharmacokinetic sampling. These sites will have non-random selection of patients. In addition to the intensive sampling of 60 patients in this PK study, all patients receiving rifapentine in Study 29 will be eligible for sparse PK sampling as part of the parent treatment protocol.