In two sites in Sweden (Linköping and Karolinska Hospital Solna, Stockholm), 25 patients with pulmonary tuberculosis will be recruited. MIC-determination of Mycobacterium tuberculosis will be performed in BACTEC 960 MGIT and drug concentration will be determined at 2, 4 and 12 weeks after treatment initiation using LC-MS/MS methodology. Sputum cultures will be obtained at 0, 2 days, 7 days, 2 weeks, 4 weeks and 8 weeks and TTP will be measured in duplicate samples. Clinical follow up according to WHO criteria will be performed 1 year after completion of treatment.