The clinical monitoring of patients on Hr-TB treatment follows similar principles to those that apply to other first-line TB regimens (Sections 5.4 and 6.8). Bacteriological monitoring of sputum generally follows the same schedule as drug-susceptible TB, with direct microscopy at months 2, 5 and 6. It is desirable, however, to perform a culture together with smear microscopy (or at least in the last month of treatment) to check for any emergent resistance, especially to rifampicin. Non-response to treatment should be investigated with DST.
Liver and kidney function and other blood tests may be necessary, based on clinical manifestations and medications in use. Electrocardiography (ECG) for patients on 6(H)REZ-Lfx is not usually required unless there are other risks for QT interval prolongation. The first-line TB agents may cause adverse drug reactions, which are mostly mild, not serious and self-limiting, or manageable with basic measures. TB practitioners are likely to be more familiar with the use of these medicines than with levofloxacin, which has a fairly good safety profile in both adults and children when used at the dose recommended in Annex I, even when taken for longer than 6 months (as in MDR-TB regimens – see Section 6.2 and Table 6.4). Dosage adjustment is recommended if creatinine clearance is below 50 mL/min, in consultation with a specialist (5). Adverse drug reactions should be reported to the spontaneous pharmacovigilance systems required by national regulations, as for other drug-related harms. In patients on regimens for Hr-TB, aDSM is not mandatory.
As with all other notifiable TB cases, patients with Hr-TB should be registered in the TB register, regardless of whether treatment has started, or whether a regimen containing second-line TB medicines is being given (26). The case may be retained in the TB register for the purposes of monitoring treatment response and interim or final outcomes. Cases without Hr-TB may be enumerated with the main drug-susceptible TB cases for the purposes of treatment outcome reporting. Hr-TB cases given fluoroquinolones or other second-line agents in addition to 6(H)REZ may also be registered in the second-line TB register if the programme wishes to monitor how many patients are being given regimens containing second-line medicines (5). If this is done, it is important that cases without RR-TB are not enumerated with the MDR/RR-TB cohort for treatment outcome monitoring purposes.
It will be helpful to monitor efforts to improve testing coverage, detection, enrolment and outcomes for Hr-TB separately from other TB or MDR/RR-TB cases. The indicators for MDR/RR-TB may be adapted for this purpose; outcome definitions are the same as for non-MDR/RR-TB (26). Reporting can be aligned to the same frequency recommended for standard monitoring of other TB cohorts.
Combining data for patients with different resistance patterns into a single cohort may complicate comparison of performance between centres and determination of trends over time, given that these patients may have different risks for treatment failure. However, treatment of TB patients who do not have rifampicin resistance with regimens discussed in this section should lead to a successful outcome in most patients, and maximizing the likelihood of success should be the end objective of TB programmes. The use of electronic case-based databases facilitates the grouping of patients by comparable resistance patterns or treatment episode to undertake more advanced analyses, allowing the adjustment for at least some covariates. Programmes are encouraged to follow good practices when collecting these data, and to participate in collaborative initiatives to share individual patient records for pooled reviews of global patient series (28–30). Such data could be useful to guide future policy on the optimization of drug-resistant TB treatment regimens.