Latent Tuberculosis Treatment
Aka: Latent Tuberculosis Treatment, Latent Tuberculosis, Latent Tb, Tuberculosis Prophylaxis, Tb Prophylaxis, LTBI
II. Epidemiology
- Concurrent HIV Infection confers a 10% conversion to Active Tuberculosis per year (highest rate)
- Overall rate of progression from Latent Tuberculosis to Active Tuberculosis: 5-15%
- Latent Tuberculosis progression is responsible for >80% of Active Tuberculosis cases in the United States
- Half of latent to Active Tuberculosis progressions occur within the first 2 years following infection
- Progression within 2 years in otherwise healthy patient (e.g. non-HIV): 5%
- Progression after 2 years in otherwise healthy patient (e.g. non-HIV): 5%
III. Precautions
- Latent Tuberculosis is a lab diagnosis based on positive Screening Tests (IGRA, PPD)
- Latent Tuberculosis are asymptomatic
- Active Tuberculosis patients are symptomatic (cough, Hemoptysis, Night Sweats, weight loss)
- Active Tuberculosis patients are treated with multi-drug regimens to prevent resistance
- Do not treat Latent Tuberculosis patients with single agent until Active Tb is excluded by history
- Latent Tb management requires provider vigilence
- Educate and monitor compliance (important to complete course)
- Be alert for hepatotoxicity (Isoniazid, rifamycins) and limit Alcohol and other Hepatotoxins
- Observe for Thrombocytopenia with rifamycins
- See specific agents for additional recommendations (e.g. Vitamin B6 and Isoniazid, Rifamycin Drug Interactions)
IV. Indications: Strongest Indications for Latent Tuberculosis Treatment
- See Tuberculosis Screening (Tuberculin Skin Test or IGRA)
- See Tuberculosis Risk Factors for progression from Latent to Active Disease
- Risk of serious disease or Extrapulmonary Tuberculosis (e.g. Miliary Tuberculosis, Tuberculous Meningitis)
V. Contraindications: Latent Tuberculosis Treatment
- Age over 35 years (risk of hepatitis) is no longer an absolute contraindication
- Prophylaxis indications regardless of age
- Recent PPD conversion
- Chest XRay shows healed Tuberculosis (see Tuberculosis Related Chest XRay Changes)
- Immunocompromised patient (e.g. HIV)
VI. Duration: Treatment
- Typical course: 9 months (unless otherwise noted – see below)
- Course of 9 months is now also recommended in cases previously treated for 12 months
- Human Immunodeficiency Virus (HIV)
- Immunosuppression
- Chest XRay showing healed Tuberculosis (e.g. apical fibronodular changes)
VII. Protocols: Latent Tuberculosis Treatment
- See Isoniazid for specific precautions and Vitamin B6 supplementation guidelines
- First Line Prophylaxis
- Duration
- Standard therapy: 9 months (90% effective)
- Shorter course: 6 months (60-80% effective, but better compliance)
- Isoniazid Routine Dosing
- Adults 5 mg/kg up to 300 mg orally daily
- Child 10-20 mg/kg/day (max 300 mg/day)
- Isoniazid Alternative Dosing
- Adult: 15 mg/kg up to 900 mg twice weekly supervised
- Child: 20-40 mg/kg twice weekly (maximum 900 mg) supervised
- Duration
- Alternative Protocols: Rifampin for 4 months (60% effective)
- Do not use as monotherapy in HIV Infection
- Allows for shorter course and lower hepatotoxicity risk
- Review Drug Interactions before use
- Very expensive (10-20 times the cost of Isoniazid)
- Rifampin Routine Dosing (intermittent dosing not recommended when used alone)
- Adults 10 mg/kg up to 600 mg orally daily for 4 months
- Child 10-20 mg/kg/day (max 600 mg/day) for 4 months
- Efficacy
- Not inferior to Isoniazid for 9 months, and better completion rates with less adverse effects
- Alternative Protocols: Short course for 12 weeks (90% effective)
- Combination of both Isoniazid (INH) and Rifapentine both weekly for 12 weeks
- Each dose must be physician observed (due to risk of drug resistant Tuberculosis if stopped early)
- Protocol
- Isoniazid (INH) 15 mg/kg up to 900 mg weekly for 12 weeks AND
- Rifapentine (Priftin) weekly for 12 weeks
- Weight 10 to 14 kg: Rifapentine 300 mg weekly
- Weight 14.1 to 25 kg: Rifapentine 450 mg weekly
- Weight 2.5.1 32 kg: Rifapentine 600 mg weekly
- Weight 32.1 to 49.9 kg: Rifapentine 750 mg weekly
- Weight >50 kg (and adults): Rifapentine 900 mg weekly
- Efficacy
- As effective and safe as other Latent Tb regimens with significantly higher completion rates
- References
- Combination of both Isoniazid (INH) and Rifapentine both weekly for 12 weeks
VIII. Protocols: Resistant Exposures
- Isoniazid Resistant Tuberculosis Exposure
- Rifampin 600 mg qd
- Ethambutol for 6-12 months
- Multi-drug resistant Tb Exposure:
- Pyrazinamide 25-30 mg/kg/day and
- Ethambutol 15-25mg/kg/day and
- Fluoroquinolones
- Ofloxacin 400mg bid or
- Ciprofloxacin 750 mg bid
IX. Protocols: Discontinued – Rifampin and Pyrazinamide
- No longer recommended for Latent Tuberculosis Treatment due to hepatotoxicity
- Details listed for historical purposes only
- Rifampin 600 mg qd for 2 months
- Pyrazinamide 25mg/kg qd for 2 months
- Higher risk of hepatotoxicity than with 6 months INH
- Observe serial Liver Function Tests closely
- Jasmer (2002) Ann Intern Med 137:640-7 [PubMed]
X. Monitoring
- See Isoniazid for toxicity related to Neuropathy and Hepatotoxicity
- See Rifampin regarding Drug Interactions
XI. References
- Orman, Moran and Swaminathan in Herbert (2016) EM:Rap 16(11): 2-3
- Hartman-Adams (2014) Am Fam Physician 89(11): 889-96 [PubMed]