Red Flags
- Active TB must be excluded BEFORE starting LTBI treatment — symptom screen, CXR, and (where indicated) sputum smear/Xpert[1]
- Pre-existing severe liver disease — defer or avoid hepatotoxic LTBI regimens; balance individual risk[1]
- Pregnancy with LTBI — defer treatment until postpartum unless very high TB risk; avoid rifapentine in pregnancy (limited data)[1]
- Recent contact of MDR-TB case — standard LTBI regimens may not be effective; specialist input on fluoroquinolone-based prophylaxis[1]
First-line treatment
Interventions
- Active screening of high-risk groups[1]Household contacts of TB cases (especially children <5 and PLHIV), healthcare workers, immunosuppressed, prisoners, healthcare-associated communities
First-line drug therapy
| Drug | Class | Adult | Paediatric | Notes |
|---|---|---|---|---|
| Rifapentine + isoniazid (3HP) | Weekly rifamycin + isoniazid | Rifapentine 900 mg + isoniazid 900 mg PO once weekly × 12 doses | Per weight, age ≥2 years per NTEP/WHO | Weekly 3HP is an NTEP preventive-treatment option for eligible people aged ≥2 years. Select it using the full programme eligibility and interaction criteria. For PLHIV, NACO May 2024 instead prefers 1HP at age ≥13 years and 6H in the specified younger-age, pregnancy/breastfeeding and protease-inhibitor ART groups. [2][3] |
| Rifapentine + isoniazid (1HP)[1] | Daily 1-month rifapentine + isoniazid | Rifapentine 600 mg + isoniazid 300 mg PO daily × 28 days | Adults and ≥13 years | Shortest regimen, PLHIV indication; high completion rate |
| Rifampicin (4R) | Daily rifampicin × 4 months | 10 mg/kg PO daily (max 600 mg) × 4 months | For eligible contacts of isoniazid-resistant, rifampicin-sensitive TB, the NTEP 2021 dosing table gives: age <10 years, rifampicin 15 mg/kg daily (range 10–20 mg/kg); age ≥10 years, 10 mg/kg daily; maximum 600 mg daily for 4 months. The 2024 addendum retains 4R for this contact group after active TB is excluded; it does not restate the 2021 limited-rollout condition. [2][3] | NTEP’s 2024 addendum lists 4 months of daily rifampicin for eligible household contacts of isoniazid mono/poly-resistant, rifampicin-sensitive TB after active disease is excluded; apply the programme’s TB-infection testing and interaction criteria. NACO 2024 also lists 4R for PLHIV with these drug-resistant TB contacts. [3] |
| Isoniazid (6H) | Daily isoniazid × 6 months | Isoniazid 5 mg/kg orally daily (maximum 300 mg) for 6 months. For those at risk of neuropathy, NTEP 2021 gives prophylactic pyridoxine 25 mg daily in adults and 50 mg daily in adults living with HIV; TPT should not be withheld solely because pyridoxine is unavailable. [2] | Isoniazid daily for 6 months: age <10 years, 10 mg/kg (range 7–15 mg/kg); age ≥10 years, 5 mg/kg; maximum 300 mg daily. [2] | Traditional regimen; lower completion rates than shorter alternatives but still effective |
Rifapentine + isoniazid (3HP)
Weekly rifamycin + isoniazid
- Adult
- Rifapentine 900 mg + isoniazid 900 mg PO once weekly × 12 doses
- Paediatric
- Per weight, age ≥2 years per NTEP/WHO
Weekly 3HP is an NTEP preventive-treatment option for eligible people aged ≥2 years. Select it using the full programme eligibility and interaction criteria. For PLHIV, NACO May 2024 instead prefers 1HP at age ≥13 years and 6H in the specified younger-age, pregnancy/breastfeeding and protease-inhibitor ART groups. [2][3]
Rifapentine + isoniazid (1HP)[1]
Daily 1-month rifapentine + isoniazid
- Adult
- Rifapentine 600 mg + isoniazid 300 mg PO daily × 28 days
- Paediatric
- Adults and ≥13 years
Shortest regimen, PLHIV indication; high completion rate
Rifampicin (4R)
Daily rifampicin × 4 months
- Adult
- 10 mg/kg PO daily (max 600 mg) × 4 months
- Paediatric
- For eligible contacts of isoniazid-resistant, rifampicin-sensitive TB, the NTEP 2021 dosing table gives: age <10 years, rifampicin 15 mg/kg daily (range 10–20 mg/kg); age ≥10 years, 10 mg/kg daily; maximum 600 mg daily for 4 months. The 2024 addendum retains 4R for this contact group after active TB is excluded; it does not restate the 2021 limited-rollout condition. [2][3]
NTEP’s 2024 addendum lists 4 months of daily rifampicin for eligible household contacts of isoniazid mono/poly-resistant, rifampicin-sensitive TB after active disease is excluded; apply the programme’s TB-infection testing and interaction criteria. NACO 2024 also lists 4R for PLHIV with these drug-resistant TB contacts. [3]
Isoniazid (6H)
Daily isoniazid × 6 months
- Adult
- Isoniazid 5 mg/kg orally daily (maximum 300 mg) for 6 months. For those at risk of neuropathy, NTEP 2021 gives prophylactic pyridoxine 25 mg daily in adults and 50 mg daily in adults living with HIV; TPT should not be withheld solely because pyridoxine is unavailable. [2]
- Paediatric
- Isoniazid daily for 6 months: age <10 years, 10 mg/kg (range 7–15 mg/kg); age ≥10 years, 5 mg/kg; maximum 300 mg daily. [2]
Traditional regimen; lower completion rates than shorter alternatives but still effective
Safety-net
- Take LTBI treatment exactly as prescribed; missed doses or premature stop reduces protection[1]
- Watch for jaundice, severe vomiting, rash, or numb hands/feet — same-day medical review (drug toxicity); pyridoxine reduces neuropathy risk on isoniazid[1]
- Tell other clinicians and your dentist that you are on rifampicin/rifapentine — many drug interactions (oral contraceptives, anticoagulants, antiretrovirals)[1]
Referral criteria
- Suspected active TB during LTBI workup (symptoms, CXR abnormality)TB specialist; do NOT give LTBI monotherapy alone[1]
- Contact of MDR-TB casePMDT centre for individualised prophylaxis[1]
- Severe ATT-related liver injury during LTBI therapyHospital admission; pause; sequential reintroduction under specialist[1]
Clinical summary
Identification and treatment of latent TB infection (LTBI) in high-risk groups; shorter rifamycin-based regimens preferred over 6-month isoniazid.
References
- 1.NTEP Guidance on TB Preventive Treatment 2024; WHO Consolidated Guidelines on Tuberculosis: Tuberculosis Preventive Treatment (2024)
- 2.Guidelines for Programmatic Management of Tuberculosis Preventive Treatment in India 2021. Official national programme guidance (2021)
- 3.NACO revised TPT guidance for PLHIV, 20 May 2024, with NTEP 1HP technical addendum. Official national programme guidance (2024)