Which medication is used in LTBI treatment in a 3-month regimen with Rifapentine?

The medication used in the treatment of latent tuberculosis infection (LTBI) in conjunction with Rifapentine for a 3-month regimen is Isoniazid. This combination has been established as effective for individuals who are at high risk of developing active tuberculosis but do not currently show symptoms of the disease.

Isoniazid works by inhibiting the synthesis of mycolic acids, which are critical components of the bacterial cell wall in Mycobacterium tuberculosis. By adding Isoniazid to Rifapentine, which is a derivative of Rifampin that also targets the bacterial RNA polymerase, the treatment regimen enhances the efficacy against the latent infection.

Other medications listed may be effective in treating active tuberculosis or may be part of different treatment regimens, but they do not specifically align with the 3-month regimen indicated in the question. Ethambutol and Pyrazinamide are usually used in multi-drug regimens for active TB, and Rifampin is typically paired with Isoniazid for longer treatment courses, not specifically with Rifapentine in a 3-month format for LTBI.