Which drug is a key component of the rifapentine-based LTBI regimen 3HP?

• A. Rifapentine.
• B. Rifampin.
• C. Isoniazid.
• D. Isoniazid and rifampin.

Answer: (A)

The main idea is recognizing which drug defines the rifapentine-based LTBI regimen called 3HP. In this regimen, the pivotal component is rifapentine, paired with isoniazid for a total of 12 weeks (once weekly). Rifapentine’s long half-life allows effective bactericidal activity with weekly dosing, which is what makes this regimen distinct from others that use rifampin alone or isoniazid alone. The weekly rifapentine–isoniazid combination provides a shorter, adherence-friendly option for latent TB infection. Other drugs listed (rifampin alone or with isoniazid, or isoniazid alone) are tied to different LTBI regimens, not the rifapentine-based 3HP.