Which drugs are used in the 3HP latent TB regimen?

• A. Isoniazid with rifapentine weekly for 12 weeks
• B. Isoniazid daily for 9 months
• C. Rifampin daily for 4 months
• D. Pyrazinamide weekly for 3 months

Answer: (A)

The key idea here is the 3HP regimen: a short, once-weekly course for latent TB infection that uses two drugs, isoniazid and rifapentine, given together for 12 weeks (12 weekly doses). The long-acting rifapentine lets dosing occur only once a week, while isoniazid provides the necessary activity against latent Mycobacterium tuberculosis. This combination is used specifically because it offers similar effectiveness to the longer INH-only regimens but with much better adherence and often a favorable safety profile for many patients.

So the correct description is isoniazid with rifapentine administered weekly for 12 weeks. The other described regimens—daily isoniazid for 9 months, daily rifampin for 4 months, or a pyrazinamide-containing approach—are different latent TB treatment courses and do not define the 3HP plan.