From Tuberculosis › Chapter 8: Tuberculosis drugs and treatment regimens · Médecins Sans Frontières, Current online edition, 2026
MSF guidance on first-line and other TB drugs used in the treatment of drug-susceptible tuberculosis.
- Issuer
- Médecins Sans Frontières
- Edition
- Current online edition, 2026
- Audience
- Clinicians treating tuberculosis patients
- Evidence
- Expert consensus based on MSF field experience
- Reviewed
- 22 Oct 2026 · GMJ
What this guideline says
GMJ summary
This section of the MSF Tuberculosis guideline describes the pharmacological agents used in treating drug-susceptible tuberculosis (DS-TB). All drugs for DS-TB are taken 7 days a week. The first-line drugs include isoniazid (bactericidal), rifamycins (rifampicin, rifabutin, rifapentine; bactericidal), ethambutol (bacteriostatic), and pyrazinamide (weakly bactericidal). Each has distinct resistance patterns, with high-level resistance to isoniazid and rifampicin documented in some regions.
The guideline emphasises that whilst these drugs are generally well tolerated at recommended doses, clinicians must remain vigilant for specific adverse effects. Isoniazid may cause peripheral neuropathy (preventable with pyridoxine), hepatotoxicity, and hypersensitivity. Rifamycins can cause hepatotoxicity, thrombocytopenia, and are strong cytochrome P450 inducers affecting many drug interactions. Ethambutol carries dose- and duration-dependent ocular toxicity risk, though this is uncommon at recommended doses for 2 months. Pyrazinamide may cause hepatotoxicity, gout, arthralgias, and photosensitivity.
Two second-line drugs—moxifloxacin and ethionamide—are also used in DS-TB treatment. Rifampicin is the most commonly used rifamycin for DS-TB, whilst rifabutin is preferred in patients on certain antiretrovirals. Rifapentine is reserved for the specific 4-month regimen 2HPZ-Mfx/2HP-Mfx.
Key points
For clinicians — doses and thresholds as stated in the guideline
- All drugs used for DS-TB treatment are taken 7 days a week
- Isoniazid peripheral neuropathy should be prevented by administration of pyridoxine (vitamin B6)
- Rifamycins are strong inducers of cytochrome P450 (CYP450) and can affect the plasma concentrations of many drugs
- Rifabutin is used instead of rifampicin in patients taking certain antiretrovirals
- Rifapentine is only used in the 4-month regimen 2HPZ-Mfx/2HP-Mfx
- Ethambutol ocular toxicity is dose- and duration-dependent and uncommon when used at recommended dose for 2 months
- High level of resistance to rifampicin occurs in some regions, with high level of cross-resistance between rifamycins
- Two second-line drugs—moxifloxacin and ethionamide—are also used in the treatment of DS-TB
Main characteristics of first-line TB drugs
Table extracted from the guideline
| TB drugs | Activity | Resistance |
|---|---|---|
| Isoniazid | Bactericidal | High level of resistance in some regions. Cross-resistance with thionamides. |
| Rifampicin, Rifabutin, Rifapentine | Bactericidal | High level of resistance to rifampicin in some regions. High level of cross-resistance between rifamycins. |
| Ethambutol | Bacteriostatic | Unknown (no reliable drug susceptibility test for ethambutol). |
| Pyrazinamide | Weakly bactericidal | High level of resistance in regions where rifampicin resistance is frequent. |
Source: Médecins Sans Frontières, Drugs for drug-susceptible tuberculosis — MSF Tuberculosis. Reproduced in summary form.
From the guideline
Verbatim
“Peripheral neuropathy should be prevented by administration of pyridoxine (vitamin B6).”
Editor’s perspective
Why this matters for Georgia and the region
Prof. Giorgi Pkhakadze, MD, MPH, PhD
Editor-in-Chief, Georgian Medical Journal · Chair, Public Health Institute of Georgia · WHO consultant, health and migration
As Editor-in-Chief of the Georgian Medical Journal and Chair of the Public Health Institute of Georgia, I recognise the critical importance of this MSF guidance for our region, where TB incidence remains above the European average and drug resistance is an ongoing concern. The most immediately actionable recommendation for Georgian clinicians is the mandatory co-administration of pyridoxine with isoniazid to prevent peripheral neuropathy—a simple, low-cost intervention that is sometimes overlooked in busy primary care settings. One realistic implementation challenge is ensuring that the full drug interaction profile of rifamycins, particularly with antiretrovirals and other commonly prescribed medications, is systematically checked in all patients, which requires accessible clinical decision support tools and pharmacist involvement in TB treatment programmes. The guidance's emphasis on 7-day-a-week dosing also requires robust directly observed therapy systems and patient adherence support, which vary considerably across urban and rural Georgian settings.
ORCID 0000-0001-7609-4515 · Perspective written for the GMJ Guidelines Library, 22 Oct 2026
Applicability
Georgia and the South Caucasus
This guidance is highly relevant for Georgia and the South Caucasus, where tuberculosis remains a significant public health concern and drug resistance patterns vary. National TB programmes in the region should consider local resistance surveillance data when selecting first-line regimens, as the guideline notes high-level resistance to isoniazid and rifampicin in some regions. The emphasis on pyridoxine co-administration with isoniazid and careful management of drug interactions with rifamycins—particularly for patients co-infected with HIV requiring antiretrovirals—is directly applicable to clinical practice in Georgia. Programmes must ensure reliable supply chains for pyridoxine and have protocols for monitoring and managing hepatotoxicity and other adverse effects, especially given the 7-day-a-week dosing schedule.
Questions this guideline answers
Quick answers
Why must all DS-TB drugs be taken 7 days a week?
MSF guidance specifies that all drugs used for DS-TB treatment are taken 7 days a week, ensuring continuous therapeutic levels and optimal bactericidal or bacteriostatic activity throughout treatment.
When should rifabutin be used instead of rifampicin?
Rifabutin is used instead of rifampicin in patients taking certain antiretrovirals, due to different drug interaction profiles. Rifampicin is the most commonly used rifamycin for DS-TB in other cases.
How can isoniazid-related peripheral neuropathy be prevented?
Peripheral neuropathy from isoniazid should be prevented by administration of pyridoxine (vitamin B6). The specific dosing is detailed in Appendix 17 of the full guideline.
Is ethambutol safe in children despite ocular toxicity risks?
Yes, ethambutol is usually well tolerated in children, particularly with respect to ocular toxicity. Ocular toxicity is dose- and duration-dependent and is uncommon when ethambutol is used at the recommended dose for 2 months.
Related on GMJ
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Drugs A–Z
Conditions A–Z
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Quality & accreditation
- ASF Laboratory — Standard 1 — Governance & Document Control
- ASF Laboratory — Standard 6 — Pre-Examination: Specimen Pathway
- ASF Laboratory — Standard 7 — Examination: Process & Safety
- ASF Laboratory — Standard 8 — Post-Examination: Reporting & Critical Values
- ASF Hospital — Standard 4 — Care & Treatment
- ASF Hospital — Standard 7 — Governance & Management
Same guideline
- Standard code for treatment regimens — MSF TuberculosisChapter 8: Tuberculosis drugs and treatment regimens
- Drug Susceptibility Pattern — Tuberculosis — MSF TuberculosisChapter 7: Case definitions
- Bacteriological status — MSF TuberculosisChapter 7: Case definitions
- High-risk groups — MSF TuberculosisChapter 6: Screening for active tuberculosis
- MSF Tuberculosis: Chapter 6.1 Introduction — Screening for active tuberculosis — MSF TuberculosisChapter 6: Screening for active tuberculosis
- Guidance for using diagnostic algorithm for pulmonary tuberculosis — MSF TuberculosisChapter 5: Diagnostic algorithm for pulmonary tuberculosis in symptomatic adolescents and adults
- Issuer
- Médecins Sans Frontières
- Guideline
- Tuberculosis
- Chapter
- Chapter 8: Tuberculosis drugs and treatment regimens
- Type
- Clinical guideline (chapter)
- Edition
- Current online edition, 2026
- Status
- Current
- Published
- 2026-10-14
- Scope
- Drugs for drug-susceptible tuberculosis
- Audience
- Clinicians treating tuberculosis patients
- Evidence
- Expert consensus based on MSF field experience
- Record history
- Created 22 Oct 2026 · updated 22 Oct 2026 · next check Apr 2027
Médecins Sans Frontières. 8.3 Drugs for drug-susceptible tuberculosis. In: Tuberculosis [guideline]. Paris: MSF; 2026 Oct 14.GMJ Guidelines Library records are original summaries written by the GMJ editorial team from the issuer’s published document and reviewed by a physician. They do not replace the full guideline. The document is the copyright of its issuer and is linked, not hosted. Spotted an error or a newer edition? Tell the Guidelines Desk.
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