The effect of anti-tuberculosis drug pharmacokinetics on QTc prolongation

•Among an observational cohort of patient being treated for drug-resistant tuberculosis, bedaquiline and delamanid based treatment regimens had a modest and similar effect on QTc prolongation.•Patients receiving bedaquiline or delamanid along with clofazamine and a fluoroquinolone had increased QTc prolongation compared to patients receiving 1 or 2 of these drugs.•Higher bedaquiline and levofloxacin concentrations were associated with a larger QTc prolongation.