| 2008 emergency update | 2011 update |
| Include at least four anti-TB drugs with either certain, or almost certain, effectiveness during the intensive phase of Tx. | Include at least four second-line anti-TB drugs likely to be effective as well as Z during the intensive phase of Tx. |
| Consider adding more drugs in patients with extensive disease or uncertain effectiveness | No evidence found to support the use of more than four second-line anti-TB drugs in patients with extensive disease. Increasing the number of second-line drugs in a regimen is permissible if the effectiveness of some of the drugs is uncertain. |
| The regimen should include Z and/or E, one FQ, one parenteral agent and second-line oral bacteriostatic anti-TB drugs (no preference of oral bacteriostatic second-line anti-TB drug was made). | The regimen should include Z, a FQ, a parenteral agent, ethionamide (or prothionamide), and cycloserine, or else PAS if cycloserine cannot be used. |
| E may be considered effective and included in the regimen if DST shows susceptibility | E may be used but is not included among the drugs making up the standard regimen. |
| Tx with group-5 drugs is recommended only if additional drugs are needed to bring the total to four | Group-5 drugs may be used but are not included among the drugs making up the standard regimen |
| Intensive phase minimum of 6 months (minimum 4 months after C conversion) for a total duration of minimum of 18 months after C conversion | Intensive phase minimum of 8 months for a total duration ≥20 months |
Z: pyrazinamide; E: ethambutol; FQ: fluoroquinolone; PAS: para-aminosalycilic acid ; C: capreomycin; Tx: treatment.