This chapter covers the strategies recommended to build an effective
regimen for drug resistant tuberculosis. Treatment outcomes for multidrug resistant
tuberculosis (MDR-TB) and beyond show a progressively lower cure rate as the
resistance pattern became more complex. Basically all treatment recommendations for
drug-resistant tuberculosis are based on expert opinion, with just a few available
clinical trials. Rifampin is the most important drug in the first line regimen; if the strain
is resistant is considered as pre-MDR TB and the patient must be treated for at least 18
months. There are two types of MDR-TB patients: patients who have never been
treated for tuberculosis in the past and that were infected with an already resistant strain
and patients previously treated for tuberculosis. The latter are much more frequent and
more difficult to treat. To design a regimen for MDR-TB the following order is
recommended: include ethambutol and/or pyrazinamide (WHO recommends the use of
pyrazinamide regardless of the results of the drug susceptibility testing); however this
drugs should not be counted as effective drugs. As a second step, a second line
injectable (amikacin, kanamycin or capreomycin) will be included. Then add a
fluoroquinolone (levofloxacin or moxifloxacin). Finally to complete the regimen add as
many drugs from Group 4 (ethionamide, cycloserine and PAS) as needed. If necessary,
include drugs from group 5. The first choice will be linezolid.
Keywords: Amikacin, Bedaquiline, Capreomycin, Clofazimine, Cycloserine, Delamanid,
Drug-resistant, Ethambutol, Ethionamide, Fluoroquinolones, Kanamycin, Linezolid,
Meropenem, New cases, PAS, Previously treated, Pyrazinamide, Treatment,
Tuberculosis.
