From the Guidelines
The recommended treatment for a patient with a positive Quantiferon (QFT) result indicating latent tuberculosis (TB) infection is isoniazid (INH) 300 mg daily for 6-9 months, or a shorter regimen of isoniazid plus rifapentine weekly for 12 weeks, as outlined in the 2020 guidelines from the National Tuberculosis Controllers Association and CDC 1.
Key Considerations
- Before starting treatment, active TB must be ruled out through symptom assessment, chest X-ray, and possibly sputum testing.
- Baseline liver function tests should be obtained, with monthly monitoring for patients with risk factors for hepatotoxicity.
- Vitamin B6 (pyridoxine) 25-50 mg daily is recommended with isoniazid to prevent peripheral neuropathy.
- Treatment completion is defined by the total number of doses taken within a specified timeframe rather than by calendar duration.
Alternative Options
- Rifampin 600 mg daily for 4 months or isoniazid plus rifampin daily for 3-4 months are alternative treatment regimens, as recommended by the World Health Organization for low TB burden countries 1.
- The choice between regimens depends on factors including potential drug interactions, patient adherence concerns, and comorbidities.
Effectiveness of Treatment
- These regimens are effective because they eliminate dormant TB bacteria before they can reactivate and cause active disease, with treatment reducing the risk of progression to active TB by 60-90% 1.
From the FDA Drug Label
PRIFTIN is indicated in adults and children 2 years and older for the treatment of latent tuberculosis infection caused by Mycobacterium tuberculosis in patients at high risk of progression to tuberculosis disease PRIFTIN must always be used in combination with isoniazid as a 12-week once-weekly regimen for the treatment of latent tuberculosis infection The recommended dose of PRIFTIN should be determined based on weight of the patient up to a maximum of 900 mg once weekly The recommended dose of isoniazid is 15 mg/kg (rounded to the nearest 50 mg or 100 mg) up to a maximum of 900 mg once weekly for 12 weeks.
The recommended treatment for a patient with a positive Quantiferon result indicating latent tuberculosis infection is PRIFTIN in combination with isoniazid for 12 weeks, with doses determined based on the patient's weight [ 2 ].
- Key considerations:
- Active tuberculosis disease should be ruled out before initiating treatment for latent tuberculosis infection.
- PRIFTIN must always be used in combination with isoniazid.
- The treatment regimen consists of a 12-week once-weekly regimen.
- Doses should be determined based on the patient's weight.
From the Research
Treatment Options for Latent Tuberculosis Infection
A patient with a positive Quantiferon (QFT) result indicating latent tuberculosis (TB) infection has several treatment options available. The recommended treatment regimens include:
- Once-weekly isoniazid plus rifapentine for 3 months 3
- Daily rifampin for 4 months 3
- Daily isoniazid plus rifampin for 3-4 months 3
- Daily isoniazid for 6-9 months 3, 4
Efficacy and Safety of Treatment Regimens
Studies have shown that the combination of rifapentine and isoniazid for 3 months is as effective as 9 months of isoniazid alone in preventing tuberculosis, with a higher treatment completion rate 5. The use of rifapentine plus isoniazid for 3 months has also been found to have a lower rate of hepatotoxicity compared to other regimens 6.
Alternative Regimens
Other regimens, such as 2 months of rifampin and pyrazinamide, have been studied, but have been found to have an unacceptably high rate of severe liver toxicity in non-HIV-infected adults 4. A 4-month rifampin regimen has been found to have better completion rates and less toxicity than 9 months of isoniazid, but more studies are needed to determine its efficacy 4.
Novel Regimens
Novel regimens, such as daily isoniazid plus rifapentine for 1 month, are being evaluated, and have shown promising results in terms of efficacy and safety 3, 7. A translational pharmacokinetic-pharmacodynamic modeling study found that a 6-week rifapentine monotherapy regimen may be as effective as, or even more effective than, combination regimens 7.