What is the recommended treatment for latent tuberculosis (TB)?

From the Guidelines

The recommended treatment for latent tuberculosis (TB) is a 3-month course of once-weekly isoniazid plus rifapentine (3HP), which consists of isoniazid (15 mg/kg, maximum 900 mg) and rifapentine (600-900 mg based on weight) taken together once weekly for 12 weeks. This regimen is preferred due to its excellent tolerability and efficacy, shorter treatment duration, and higher completion rates compared to longer regimens, as stated in the guidelines for the treatment of latent tuberculosis infection: recommendations from the National Tuberculosis Controllers Association and CDC, 2020 1.

Alternative Regimens

Alternative regimens include:

• 4 months of daily rifampin (10 mg/kg, maximum 600 mg), which has fewer side effects than isoniazid-based treatments
• 3 months of daily isoniazid plus rifampin (3HR)
• 6 months of daily isoniazid (5 mg/kg, maximum 300 mg)
• 9 months of daily isoniazid (5 mg/kg, maximum 300 mg)

These regimens are effective but may have concerns regarding longer treatment duration, lower completion rates, and therefore lower effectiveness, as noted in the guidelines 1.

Special Considerations

Special considerations for treatment of LTBI apply to certain populations, such as:

• Persons with HIV infection or those with radiographic evidence of prior TB, who may require 9 months of isoniazid rather than 6 months 1
• Pregnant, HIV-negative women, who may be treated with isoniazid given daily or twice weekly for 9 or 6 months 1
• Children and adolescents, who may be treated with isoniazid given either daily or twice weekly for 9 months 1

Monitoring and Side Effects

Patients should be monitored for side effects, particularly liver toxicity, with baseline liver function tests recommended before starting therapy, as stated in the guidelines for the treatment of latent tuberculosis infection: recommendations from the National Tuberculosis Controllers Association and CDC, 2020 1. Vitamin B6 (pyridoxine, 25-50 mg daily) is often prescribed with isoniazid to prevent peripheral neuropathy.

Importance of Treatment

These treatments are essential because they reduce the risk of progression to active TB disease by 60-90%, targeting the dormant bacteria before they can cause symptomatic disease and become transmissible to others, as noted in the guidelines for the treatment of latent tuberculosis infection: recommendations from the National Tuberculosis Controllers Association and CDC, 2020 1.

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 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 treatment for latent tuberculosis (TB) is not explicitly stated in the provided drug labels. However, for active tuberculosis, a three-drug or four-drug regimen is recommended.

• The three-drug regimen consists of rifampin, isoniazid, and pyrazinamide.
• The four-drug regimen adds either streptomycin or ethambutol to the three-drug regimen. It is essential to note that the treatment of latent TB may differ from that of active TB, and the provided drug labels do not directly address the treatment of latent TB 2 2.

From the Research

Treatment Options for Latent TB

The treatment of latent tuberculosis (TB) infection is crucial for preventing the development of active TB disease. Several treatment regimens are available, including:

• 9-month regimen of isoniazid monotherapy 3, 4, 5, 6, 7
• 3-4 month regimens of isoniazid plus rifampin 3, 6
• 4-month regimen of rifampin alone 4, 6
• 3-month regimen of rifapentine and isoniazid 5, 6

Efficacy and Safety of Treatment Regimens

Studies have shown that:

• A 9-month course of isoniazid monotherapy is effective in preventing active TB, but has poor adherence rates and toxic effects 3, 4
• Shorter regimens, such as 3-4 months of isoniazid plus rifampin, or 4 months of rifampin alone, have similar efficacy and better safety profiles compared to 9-month isoniazid monotherapy 3, 4, 6
• The 3-month regimen of rifapentine and isoniazid has been shown to be noninferior to 9 months of isoniazid alone, with higher treatment completion rates and better safety 5, 6

Treatment Completion Rates and Adverse Events

Research has demonstrated that:

• Treatment completion rates are higher for shorter regimens, such as 3-4 months of isoniazid plus rifampin, or 4 months of rifampin alone, compared to 9-month isoniazid monotherapy 3, 4, 5
• Adverse events, including hepatotoxicity, are less common with shorter regimens, such as 3-4 months of isoniazid plus rifampin, or 4 months of rifampin alone, compared to 9-month isoniazid monotherapy 3, 4, 5