What is the recommended management of a positive exposure to Tuberculosis (TB)?

From the Guidelines

The recommended management of positive exposure to tuberculosis (TB) involves prompt evaluation and treatment for latent TB infection (LTBI) with the preferred regimen being isoniazid (INH) 300mg daily plus rifapentine 900mg weekly for 3 months (3HP regimen) 1. After confirmed exposure, individuals should undergo a tuberculin skin test (TST) or interferon-gamma release assay (IGRA) to determine infection status. If positive, a chest X-ray should be performed to rule out active TB disease. Alternative options for LTBI treatment include INH 300mg daily for 6-9 months, or rifampin 600mg daily for 4 months 2, 1. Treatment should be initiated after active TB is excluded. Patients should be monitored for medication side effects, particularly hepatotoxicity, with baseline liver function tests and monthly follow-up for symptomatic individuals 3. Adherence to the complete treatment course is crucial to effectively prevent progression to active TB disease. This preventive therapy is especially important for high-risk groups including immunocompromised individuals, recent contacts of TB cases, and those with medical conditions that increase TB risk, as it reduces the likelihood of developing active TB by 60-90% 1, 4, 3. Some key points to consider in the management of LTBI include:

• The use of a 3-month regimen of rifampin plus isoniazid as an alternative to the standard 9-month isoniazid regimen 1
• The importance of directly observed therapy to ensure adherence to the treatment regimen 3
• The need to consider potential drug interactions, particularly with antiretroviral therapy in HIV-infected individuals 3
• The recommendation to use pyridoxine in conjunction with isoniazid to prevent peripheral neuropathy 3

From the FDA Drug Label

Rifampin is indicated in the treatment of all forms of tuberculosis A three-drug regimen consisting of rifampin, isoniazid, and pyrazinamide is recommended in the initial phase of short-course therapy which is usually continued for 2 months The Advisory Council for the Elimination of Tuberculosis, the American Thoracic Society, and the Centers for Disease Control and Prevention recommend that either streptomycin or ethambutol be added as a fourth drug in a regimen containing isoniazid (INH), rifampin, and pyrazinamide for initial treatment of tuberculosis unless the likelihood of INH resistance is very low

The recommended management of positive exposure to TB is not explicitly stated in the provided drug labels. However, for the treatment of tuberculosis, a three-drug regimen consisting of rifampin, isoniazid, and pyrazinamide is recommended in the initial phase of short-course therapy, which is usually continued for 2 months. Additionally, either streptomycin or ethambutol may be added as a fourth drug in the regimen, depending on the likelihood of INH resistance 5.

From the Research

Recommended Management of Positive Exposure to TB

The management of positive exposure to TB involves the treatment of latent tuberculosis infection (LTBI) to prevent the progression to active TB disease. The following are the recommended management strategies:

• Treatment regimens for LTBI include: + Once-weekly isoniazid plus rifapentine for 3 months 6 + Daily rifampin for 4 months 6 + Daily isoniazid plus rifampin for 3-4 months 6 + Daily isoniazid for 6-9 months 6
• The U.S. Preventive Services Task Force recommends testing individuals at increased risk of LTBI with an interferon-gamma release assay or tuberculin skin testing 7
• After a positive test result, chest radiography should be performed and, in patients with suspected pulmonary TB disease, sputum collected for diagnosis 7
• Preferred treatment regimens for LTBI include isoniazid in combination with rifapentine or rifampin, or rifampin alone for a duration of three and four months, respectively 7

Special Considerations

• For HIV-infected individuals, treatment of LTBI reduces the risk of active TB, especially in those with a positive tuberculin skin test 8
• The choice of regimen will depend on factors such as availability, cost, adverse effects, adherence, and drug resistance 8
• For individuals at high risk of developing active diseases from LTBI, such as those with HIV infections/AIDS, patients treated with TNF-α antagonists, and patients receiving long-term hemodialysis/peritoneal dialysis, specific treatment regimens and timing are recommended 9

Treatment Regimens for Specific Populations

• For HIV infections/AIDS patients with LTBI, 6H, 9H, 3HR, and 3H2P2 regimens could be used 9
• For patients treated with TNF-α antagonists and with LTBI, 3HR and 3H2P2 regimen is recommended 9
• For patients receiving long-term hemodialysis or peritoneal dialysis and with LTBI, 6H regimen is recommended as the preferred regimen 9
• For recipients who are planning to receive organ transplantation or bone marrow transplantation and with LTBI, 9H regimen is recommended 9