From the Guidelines
The 4-month ATT regimen consists of rifapentine, moxifloxacin, isoniazid, and pyrazinamide, and is recommended as a treatment option for patients aged ≥12 years with drug-susceptible pulmonary TB. This regimen is based on a randomized controlled trial published in 2022, which showed that the 4-month regimen was as effective as the standard 6-month regimen for TB treatment 1. The medications included in this regimen are rifapentine, moxifloxacin, isoniazid, and pyrazinamide, which work together to target different aspects of TB bacteria.
Key Components of the Regimen
- Rifapentine: disrupts RNA synthesis
- Moxifloxacin: inhibits DNA gyrase
- Isoniazid: inhibits cell wall synthesis
- Pyrazinamide: active against semi-dormant bacilli
Implementation Considerations
- The regimen is suitable for patients aged ≥12 years with drug-susceptible pulmonary TB
- Regular monitoring for adverse effects, including liver function tests and vision checks, is essential during treatment
- The 4-month regimen offers advantages over the traditional 6-month therapy, including better patient adherence, reduced medication burden, and fewer potential side effects, as reported in the study published in the Morbidity and Mortality Weekly Report 1.
From the FDA Drug Label
The current recommendation of the CDC for drug-susceptible disease is to use a six-month regimen for initial treatment of active tuberculosis, consisting of isoniazid, rifampin and pyrazinamide given for 2 months, followed by isoniazid and rifampin for 4 months. TUBERCULOSIS: The standard regimen for the treatment of drug susceptible tuberculosis has been two months of INH, rifampin and pyrazinamide followed by four months of INH and rifampin
The 4 months ATT regimen is isoniazid and rifampin given for 4 months, after an initial 2 months of isoniazid, rifampin, and pyrazinamide 2 3.
- Key components:
- Isoniazid
- Rifampin
- Duration: 4 months
- Preceded by: 2 months of isoniazid, rifampin, and pyrazinamide
From the Research
4-Month ATT Regimen
- The 4-month ATT regimen is a shortened treatment regimen for drug-sensitive pulmonary tuberculosis, which has been studied in several clinical trials 4, 5.
- This regimen typically consists of isoniazid, rifampicin, pyrazinamide, and ethambutol (HRZE) for 2 months, followed by a combination of drugs for an additional 2 months 4.
- Some studies have investigated the use of fluoroquinolones, such as moxifloxacin or gatifloxacin, as part of the 4-month regimen, either by replacing ethambutol or isoniazid 4.
- The evidence suggests that 4-month ATT regimens that replace ethambutol with moxifloxacin or gatifloxacin, or isoniazid with moxifloxacin, may increase the risk of relapse compared to standard 6-month ATT regimens 4.
Comparison to Standard 6-Month Regimen
- The standard 6-month regimen for drug-sensitive pulmonary tuberculosis typically consists of HRZE for 2 months, followed by isoniazid and rifampicin for 4 months 4, 6.
- Studies have compared the efficacy and safety of 4-month ATT regimens to the standard 6-month regimen, with mixed results 4, 5.
- Some studies have found that 4-month regimens may be associated with a higher risk of relapse, while others have found no significant difference in treatment outcomes 4, 5.
Safety and Efficacy
- The safety and efficacy of 4-month ATT regimens have been evaluated in several clinical trials, with a focus on the risk of relapse, treatment failure, and adverse events 4, 5.
- The evidence suggests that 4-month regimens may be associated with a higher risk of relapse, but may not increase the risk of treatment failure or adverse events 4.
- However, the results of these studies should be interpreted with caution, as the evidence is not yet conclusive and more research is needed to fully understand the safety and efficacy of 4-month ATT regimens 4, 5.