CDC Updates Recommendations of 3HP for Latent TB Infections

Treatment of latent tuberculosis infection (LTBI) is critical for the control and elimination of tuberculosis disease (TB), which remains a significant public health issue around the world. To this end, the US Centers for Disease Control and Prevention (CDC) have issued new recommendations on treatment of LTBI with once weekly isoniazid rifapentine for 12 weeks (3HP) to include more populations.

In 2011, the CDC recommended the regimen of 3HP for treatment of LTBI with limitations for children under the age of 12 and individuals with HIV.

In 2017, a CDC Work Group of epidemiologists, health scientists, and physicians from CDC’s Tuberculosis Elimination program conducted a systematic review and meta-analysis of the 3HP regimen, specifically in relation to the populations of individuals with HIV and children under the age of 12. The results indicated that 3HP is as safe and effective as other recommended LTBI regimens in these populations and achieves significantly higher treatment completion rates.

A total of 19 articles, representing 15 unique studies, were included in the meta-analysis, all of which were retrieved through a systematic search strategy of studies on the use of 3HP to treat LTBI published between January 2006 and June 2017. Data retrieved from the articles included patient demographics, benefits, harms, and evidence gaps.

The work group recommendations were based heavily on the results of a study of 3HP in children aged 2 to 7 which indicated that 3HP was well-tolerated and as effective as 9 months of daily isoniazid and also had higher completion rates.

Other heavily weighted studies focused on the use of 3HP in individuals with HIV (including those with AIDS), which found effectiveness of the treatment in individuals not taking antiretroviral therapy, and “demonstrated the absence of clinically significant drug interactions between once-weekly rifapentine and either efavirenz or raltegravir in persons with HIV infection who are treated with those antiretroviral medications.”

Additionally, the work group cited a randomized clinical trial that demonstrated noninferiority of self-administered treatment of 3HP compared with directly observed treatment in patients over the age of 18.

Following the evidence from the systematic review and TB / LBTI expert recommendations which include the use of 3HP in adults, as well as:

1. Children with LTBI aged 2 to 17 years;
2. Individuals with LTBI who have HIV infection (including AIDS), and are taking antiretroviral medications with acceptable drug-drug interactions with rifapentine; and
3. By directly observed therapy or self-administered therapy in individuals over the age of 2 years.

In addition to the new guidelines, the CDC indicates that health care providers should choose the mode of administering 3HP based on individual patient’s needs. Patients should be monitored monthly to assess treatment adherence and baseline hepatic chemistry blood tests should be ordered for patients with HIV and liver disorders.