Advances in Treatment of Latent TB Infection: What Is the Latest Approach to Treat Latent TB Infection to Prevent Pulmonary TB?

An estimated one-quarter of the world population has latent TB infection (LTBI) and 5–10% of those will develop TB disease during their lifetime. Treatment of LTBI can decrease the risk of developing TB disease by 60–90%. Historically, daily isoniazid (INH) for 6–9 months was commonly used to treat LTBI, but this regimen has a relatively high risk of drug-induced liver injury and a low rate of treatment completion. Rifamycin-based regimens (3 months of once weekly INH and rifapentine, 4 months of daily rifampin, and 3 months of daily INH and rifampin) are now preferred because of their effectiveness, safety, and high treatment completion rates. Pretreatment evaluation includes ruling out TB disease as well as assessing the risk for adverse effects and drug–drug interactions. A regimen of 4 months of daily rifampin (4R) is a preferred treatment because of a lower rate of treatment discontinuation, a lower rate of hepatotoxicity and a higher rate of treatment completion, but no evidence is available for its effectiveness in HIV-positive persons. A regimen of 3 months of once weekly INH plus rifapentine (3HP) is also a preferred treatment for adults and children aged >2 years, including HIV-positive persons. However, 3HP is associated with a systemic drug reaction including syncope and hypotension and more discontinuation because of adverse effects.