QTc Prolongation Risks in Drug-Resistant Tuberculosis: A Closer Look at Contributing Factors

Drug-resistant tuberculosis (DR-TB) presents treatment challenges due to the toxicity of prolonged multidrug regimens, particularly the risk of QTc interval prolongation and arrhythmias. This study aimed to identify factors associated with QTc prolongation in DR-TB patients. A retrospective analysis was conducted on patients treated at RS Labuang Baji and RS Tajuddin Chalid Makassar between January 2020 and December 2024. Included were patients over 16 years with complete ECG and lab data, excluding those with baseline QTc >450 ms or concurrent QT-prolonging medications. QTc was calculated using Fridericia’s formula. Of 317 patients, 30.6% showed QTc prolongation. Significant associations were found with older age, overweight BMI, diabetes (OR 3.38), hypertension (OR 6.53), and electrolyte imbalances (Na⁺, K⁺, Cl⁻). The use of Bedaquiline, Levofloxacin, and Clofazimine increased the risk of QTc prolongation individually and in combination (p < 0.001). These findings highlight the need for careful ECG monitoring in DR-TB patients, especially those with comorbidities or receiving QT-prolonging drugs.