All drugs used for DS-TB treatment are taken 7 days a week.
8.3.1 First-line drugs
Table 8.2 – Main characteristics of first-line TB drugs
TB drugs |
Activity |
Resistance |
---|---|---|
Isoniazid |
Bactericidal |
|
Rifampicin Rifabutin Rifapentine |
Bactericidal |
|
Ethambutol |
Bacteriostatic |
Unknown (no reliable drug susceptibility test for ethambutol). |
Pyrazinamide |
Weakly bactericidal |
High level of resistance in regions where rifampicin resistance is frequent. |
Isoniazid
Isoniazid is usually well tolerated at recommended doses.
It may cause peripheral neuropathy, hepatotoxicity, and hypersensitivity reactions.
Peripheral neuropathy should be prevented by administration of pyridoxine (vitamin B6). See Appendix 17.
Rifamycins (rifampicin, rifabutin, rifapentine)
Rifamycins are usually well tolerated at recommended doses.
They may cause hypersensitivity reactions, hepatotoxicity, and thrombocytopenia.
They are strong inducers of cytochrome P450 (CYP450) and can affect the plasma concentrations of many drugs (Appendix 19).
Rifampicin is the most used rifamycin in the treatment of DS-TB.
Rifabutin is used instead of rifampicin in patients taking certain antiretrovirals (Appendix 19).
Rifapentine is only used in the 4-month regimen 2HPZ-Mfx/2HP-Mfx.
Note: rifampicin and rifapentine are also used to treat latent TB infection (Chapter 16).
Ethambutol
Ethambutol is usually well tolerated, including in children, particularly with respect to ocular toxicity
[1]
Citation
1.
World Health Organization. Guidance for national tuberculosis programmes on the management of tuberculosis in children. Geneva: World Health Organization; 2014.
https://apps.who.int/iris/bitstream/handle/10665/112360/9789241548748_eng.pdf?sequence=1
. Ocular toxicity is dose- and duration-dependent. It is uncommon when ethambutol is used at the recommended dose for 2 months.
Pyrazinamide
Pyrazinamide is usually well tolerated however, it may cause hepatotoxicity, gout, arthralgias and photosensitivity.
8.3.2 Other drugs
Two second-line drugs are also used in the treatment of DS-TB: moxifloxacin (Section 8.4.1) and ethionamide (Section 8.4.3).
- 1.World Health Organization. Guidance for national tuberculosis programmes on the management of tuberculosis in children. Geneva: World Health Organization; 2014.
https://apps.who.int/iris/bitstream/handle/10665/112360/9789241548748_eng.pdf?sequence=1