Table 2 Changes to the recommendations on regimen composition between the 2008 and 2011 updates of WHO MDR-TB guidelines
2008 emergency update2011 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 effectivenessNo 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 susceptibilityE 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 fourGroup-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 conversionIntensive 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.