Patients who receive BPaLM/BPaL need to be tested at baseline and then monitored during treatment using schedules of relevant clinical and laboratory testing. If feasible, it is also important to follow up patients 12 months after the completion of treatment for possible relapse, including with sputum culture and smear.
The bacteriological status of the patient should be available before treatment initiation, with confirmation of TB disease and rifampicin resistance as a minimum if possible. It is recommended to monitor patients with MDR/RR-TB while on treatment using monthly sputum cultures. Failure to convert sputum culture at or after the fourth month on treatment is a potential sign of a failing treatment regimen. The DST for fluoroquinolones is important to support prescription of the relevant combination, BPaLM or BPaL, to maximize the efficacy and prevent unnecessary potential toxicity. Country programmes are also strongly encouraged to establish the DST capacity to test for resistance to bedaquiline and linezolid at baseline (particularly in cases demonstrating fluoroquinolone resistance) and to test samples from patients with no bacteriological conversion after month 4 while on the BPaLM/BPaL regimen.
It is good practice to assess patients for symptoms and signs of liver disease (e.g. fatigue, anorexia, nausea, jaundice, dark urine, liver tenderness and hepatomegaly), peripheral or optic neuropathy and conduct laboratory tests such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and bilirubin, complete blood count and serum potassium, calcium and magnesium (which should be corrected if abnormal). Treating clinicians are also advised to obtain an ECG before initiation of treatment. A suggested schedule of monitoring is provided in the operational handbook on treatment of DR-TB (3).
The WHO framework for aDSM needs to be applied to patients on any type of MDR-TB regimen, to ensure an acceptable level of monitoring for adverse events and prompt response to such events – alongside monitoring for treatment outcomes, including early monitoring for treatment failure. Additional evidence generated on adverse events will be important to build the evidence base on the safety of the new regimens in varied settings.
Monitoring of changes in dosing and duration of linezolid in particular (when needed) will also be important, to inform the future evidence base on the wider use of the BPaLM/BPaL regimen and the tolerability of linezolid in this regimen.