Isoniazid and rifampicin exposure during treatment in drug-susceptible TB.

Observational real-world studies on therapeutic drug monitoring (TDM) in relation to pharmacokinetic (PK) target values are lacking. This study aims to describe the PK of rifampicin (RIF) and isoniazid (INH) in a real-world setting of patients with drug-susceptible TB in relation to frequently used threshold values. A total of 116 patients with TB using standard doses of RIF and INH and who had TDM as part of clinical care were included.