Tuberculosis Treatment Pathway (NTEP)

Undernutrition is the single leading driver of TB mortality in India. The RATIONS trial (Bhargava et al., Lancet 2023) showed that supplementing the household contacts of a patient with pulmonary tuberculosis reduced their tuberculosis incidence by 39% for all forms and 48% for microbiologically confirmed pulmonary disease. In the patient cohort nested in the same trial (Lancet Glob Health 2023), a 5% weight gain by two months was associated with an adjusted hazard ratio for death of 0.39. Providing specific macro- and micro-nutritional targets alongside ATT is a critical standard of care, not optional supportive therapy.

1. The "RIPE" Mnemonic for First-Line Toxicity

• R - Rifampicin: Red/Orange secretions, Rapid CYP450 induction (most potent inducer in clinical medicine).
• I - Isoniazid (INH): Injures Nerves (peripheral neuropathy - always give B6), Injures Hepatocytes (hepatitis).
• P - Pyrazinamide: Polyarthralgia (hyperuricaemia), most Potent hepatotoxin of the four.
• E - Ethambutol: Eye issues (retrobulbar optic neuritis, red-green colour blindness). Baseline visual acuity is mandatory.

2. Fixed-Dose Combination Quality in the Private Sector

3. ATT-Induced Hepatitis: The Rechallenge Protocol

• When to stop ALL ATT: AST/ALT exceeds 5x ULN (asymptomatic) or exceeds 3x ULN with hepatitis symptoms (nausea, vomiting, anorexia, jaundice).
• Wait: Observe until LFTs normalise or fall below 2x ULN and symptoms resolve completely.
• Rechallenge order: Reintroduce drugs sequentially, one at a time, with 3 to 7 days between each: R first (least hepatotoxic), then H, then Z last (most hepatotoxic). If hepatitis recurs with a specific agent, omit it permanently and substitute.
• Never rechallenge Pyrazinamide if it was the identified culprit. Extend treatment duration instead.

Working through an actual case? The ATT-Induced Liver Injury & Rechallenge pathway carries the bridging regimen and the sequential rechallenge schedule.

4. DR-TB Classification Definitions (NTEP 2025)

• DS-TB: Pan-susceptible to all first-line drugs.
• H-Mono/Poly DR-TB: Resistant to Isoniazid (H), susceptible to Rifampicin (R). FL-LPA is what confirms it.
• MDR/RR-TB: Resistant to Rifampicin (with or without H resistance), but susceptible to Fluoroquinolones (FQ).
• Pre-XDR TB: MDR/RR-TB with additional resistance to any Fluoroquinolone.
• XDR TB: Pre-XDR TB with additional resistance to Bedaquiline (Bdq) and/or Linezolid (Lzd).

5. Active Drug Safety Monitoring (aDSM)

6. The BPaL / BPaLM Shift

NTEP prioritises the shorter all-oral regimens: BPaLM for MDR, BPaL for Pre-XDR. Both are strictly contraindicated below 14 years of age and in severe EPTB. Where either applies, the tool routes the patient to the 18 to 20 month Longer Oral Regimen instead.

7. Dietary Bioavailability Cautions

Food decides how much of a dose actually gets in, and it does not act the same way on every drug. Rifampicin Cmax is blunted by a meal, and the low peak that follows is one of the routes to acquired resistance. Bedaquiline goes the other way: absorption increases nearly two-fold with a high-fat meal.

8. NTEP Weight Bands

The bands are calibrated to deliver therapeutic mg/kg doses across the range of body weights each one covers. A child or adolescent up to 18 years weighing under 40 kg is dosed on the paediatric bands; above 39 kg they move to the adult bands.

9. What This Pathway Does Not Print

• A bridging regimen, or the dates of a sequential rechallenge. Section 3 gives the rule; the ATT-DILI pathway carries the schedule.
• A brand or a manufacturer. Section 2 says to move to NTEP-supplied FDCs or to loose drugs, and names no product.