1 | Chose an injectable (group 2) | Kanamycin Amikacin Capreomycin | Choose a drug based on DST and treatment history Streptomycin is generally not used because of high rates of resistance in patients with MDR-TB |
2 | Choose a higher-generation fluoroquinolone (group 3) | Levofloxacin Moxifloxacin | Use a later-generation fluoroquinolone If levofloxacin (or ofloxacin) resistance is documented, use moxifloxacin Avoid moxifloxacin if possible when using bedaquiline |
3 | Add group 4 drugs | Cycloserine/terizidone PAS Ethionamide/prothionamide | Add two or more group 4 drugs until there are at least four second-line anti-TB drugs likely to be effective Ethionamide/prothionamide is considered the most effective group 4 drug Consider treatment history, side-effect profile and cost DST is not considered reliable for the drugs in this group |
4 | Add group 1 drugs | Pyrazinamide Ethambutol | Pyrazinamide is routinely added in most regimens Ethambutol can be added in the case of full sensitivity If isoniazid DST is unknown or pending it, can be added to the regimen until DST results become available |
5 | Add group 5 drugs | Bedaquiline Linezolid Clofazimine Amoxicillin/clavulanate Imipenem/cilastatin plus clavulanate Meropenem plus clavulanate High-dose isoniazid Clarithromycin Thioacetazone | Consider adding group 5 drugs if four second-line anti-TB drugs are not likely to be effective from groups 2–4 If drugs are needed from this group, it is recommended to add two or more DST is not standardised for the drugs in this group |
DST: drug susceptibility testing; PAS: p-aminosalicylic acid. Information from [19].