From the Guidelines
The latent TB treatment should last 3-4 months with a rifamycin-based treatment regimen, as it is preferred over the longer-course isoniazid monotherapy due to better completion rates and effectiveness. The treatment duration for latent tuberculosis infection (LTBI) can vary depending on the chosen medication regimen. According to the guidelines for the treatment of latent tuberculosis infection published in 2020 by the National Tuberculosis Controllers Association and CDC 1, short-course rifamycin-based treatment regimens are recommended for patients without drug intolerability or drug-drug interactions. Some key points to consider when treating LTBI include:
- The preferred treatment regimens are short-course (3–4 months) rifamycin-based treatments, which have better completion rates and effectiveness compared to longer-course (6–9 months) isoniazid monotherapy 1.
- The choice of regimen depends on factors such as the patient's age, potential drug interactions, risk of liver disease, and suspected drug resistance of the TB strain.
- Regular monitoring for side effects, particularly liver function tests for those on isoniazid, is important during treatment.
- Completing the entire course of treatment is crucial, even if the patient feels well, as partial treatment may not fully eliminate the dormant TB bacteria. These guidelines can be used by clinicians, public health officials, policymakers, health care organizations, and other state and local stakeholders who might need to adapt these guidelines for individual clinical circumstances, as stated in the guidelines published by the National Tuberculosis Controllers Association and CDC in 2020 1.
From the FDA Drug Label
PRIFTIN should be administered once weekly in combination with isoniazid for 12 weeks as directly observed therapy. The latent TB treatment with rifapentine (PRIFTIN) is 12 weeks long, administered once weekly in combination with isoniazid 2.
- The treatment duration is fixed at 12 weeks, regardless of patient weight or age (above 2 years).
- The dose of PRIFTIN and isoniazid may vary based on patient weight, but the treatment duration remains the same.
From the Research
Latent TB Treatment Duration
The duration of latent TB treatment can vary depending on the regimen used. Some of the commonly used regimens and their durations are:
- 9 months of daily self-administered isoniazid (INH) 3
- 2 months of rifampin and pyrazinamide, although this regimen is associated with severe liver toxicity in non-HIV-infected adults 3
- 3-4 months of INH and rifampin, which has equivalent effectiveness to 6 months of INH 3
- 4 months of rifampin, which has better completion rates and less toxicity than 9 months of INH 3
- 3 months of once-weekly isoniazid and rifapentine, which has been shown to be noninferior to 9 months of daily isoniazid 4, 5
- 1 month of daily isoniazid plus rifapentine, which is currently under evaluation 6
Treatment Completion Rates
Treatment completion rates can vary depending on the regimen used. Some of the completion rates reported in studies are:
- 69.0% for 9 months of self-administered daily isoniazid 5
- 82.1% for 3 months of once-weekly isoniazid and rifapentine 5
- Significantly better completion rates for 4 months of rifampin compared to 9 months of INH 3
Efficacy of Treatment Regimens
The efficacy of different treatment regimens for latent TB has been evaluated in several studies. Some of the findings are:
- 9 months of INH has an efficacy of more than 90% if completed properly 3
- 3 months of once-weekly isoniazid and rifapentine is as effective as 9 months of INH alone in preventing tuberculosis 5
- 4 months of rifampin has been found to have significantly better completion rates and less toxicity than 9 months of INH, although only one trial has evaluated its efficacy and effectiveness 3