The first case is a 57-year-old known Human Immunodeficiency Virus (HIV)-positive and chronic obstructive pulmonary disease (COPD) patient who was relatively stable and on treatment for both conditions. He was diagnosed with MDR-TB in January 2017 after two prior successful treatment courses for drug-susceptible TB in 2014 and 2018 respectively. He was started on a MDR-TB regimen of levofloxacin-delamanid-prothionamide-cycloserine and clofazimine after inpatient stabilization of initial respiratory distress. His baseline QTcF-interval was 416 msec but increased to 523 msec after one month of MDR-TB treatment. Patient was not having any cardiac symptoms, did not have any evidence of electrolyte disorders, organ injury or endocrine abnormalities on laboratory tests and was not taking any concomitant medicines known to prolong the QT-Interval as well (Rohan J et al., 2002). Hence, he was observed for spontaneous resolution with frequent ECG monitoring. Despite this the QTcF persisted above 500 msec and finally clofazimine was stopped after 10 days of observation. Follow up QTcF recorded on wards kept on falling and normalized after a week of clofazimine discontinuation. Afterwards, the patient never had prolonged QTcF for the rest duration of treatment until discharged with an outcome of cure at 18 months.