Tuberculosis Chemoprophylaxis: Preventing Active TB in High-Risk Groups

TB chemoprophylaxis (preventive therapy) uses antibiotics to halt progression from latent TB infection (LTBI) to active disease.

Standard Regimens

• Isoniazid (INH) 9 months (daily/biweekly) – gold standard.
• INH + Rifapentine weekly × 12 weeks (3HP) – shorter, higher completion.
• Rifampin 4 months (4R) – alternative if INH intolerant.

Indications

• Close contact with infectious TB case
• LTBI + HIV, diabetes, CKD, TNF-α inhibitors, transplant, silicosis
• Children <5 with LTBI
• Pregnant women with recent exposure

Monitoring

• Monthly symptom review, LFTs (baseline + periodic if risk factors).
• Adherence counseling critical.

Prevents individual disease and community transmission.