Which drug is commonly used for latent TB in a 4-month regimen?

• A. Isoniazid
• B. Rifampin
• C. Pyrazinamide
• D. Ethambutol

Answer: (B)

Latent TB treatment aims to prevent progression to active disease with a regimen that is both effective and tolerable. A 4-month course of rifampin is commonly used because it provides strong protection against reactivation in a much shorter time than the traditional 9-month isoniazid regimen. The shorter duration improves patient adherence and reduces the cumulative risk of hepatotoxicity associated with long-term isoniazid therapy. While rifampin is favored for this LTBI regimen, be mindful of drug interactions due to its enzyme-inducing effects. Isoniazid is the older LTBI option administered for 9 months, whereas pyrazinamide and ethambutol are typically part of regimens for active TB, not used alone as a 4-month latent therapy.