Tolerance to chemotherapy regimens with bedaquiline in adolescents with MDR/XDR pulmonary TB

<b>Relevance:</b> Chemotherapy of multi- or extensively drug resistant TB (MDR/XDR TB) is recognized a complicated and pressing issue worldwide. Currently there are not enough data to decide on the duration of chemotherapy or the safety of novel drugs, first of all, bedaquiline, in children and adolescents. <b>Aim:</b> To study the safety of bedaquiline (Bdq) in chemotherapy regimens for MDR/XDR TB patients. <b>Materials and methods:</b> We conducted a cohort prospective study of 35 patients aged 13-18 years with MDR/XDR pulmonary TB in 2016-2020. The indications for Bdq administration were: impossibility to compose an effective chemotherapy regimen due to DST results and/or development of intractable adverse reactions to TB drugs. We monitored Bdq tolerance: ECG with the QT interval measurements (the normal range for children 0-18 years old is 0.36-0.44 sec.) was performed weekly during the first month, monthly afterwards. Informed consents from the patients’ parents for Bdq administration were obtained. <b>Results:</b> Bdq was indicated for the treatment of 14 (40%) out of 35 patients with MDR/XDR TB. Four patients (29%) received Bdq for 24 weeks, 10 patients (71%) – for 48 weeks. Out of 14 patients good Bdq tolerance was observed in 12 (86%); in 2 patients (14%) prolonged QT interval to 0.460 and 0.466 sec. was observed at week 4 and week 34, Bdq was withdrawn. The ECG parameter normalized one week after Bdq withdrawal. <b>Measurements and Main Results:</b> We observed good tolerance to the chemotherapy regimens with Bdq in 86% of the patients, even when the drug was received for 48 weeks.