American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended treatment for a patient with HIV who has a Tuberculin Skin Test (TST) result greater than 5 mm?

1. Rifampin 600 mg/d for 6 months

2. INH, 300 mg/d for 9 months

3. Pyrazinamide 25 mg/kg/d for 2 months

4. Ethambutol 15 mg/kg/d for 12 months

The correct answer is: INH, 300 mg/d for 9 months

In the setting of a patient with HIV who has a Tuberculin Skin Test (TST) result greater than 5 mm, the recommended treatment is Isoniazid (INH) at a dosage of 300 mg daily for 9 months. This recommendation comes from guidelines and clinical standards for the prevention of tuberculosis (TB) in individuals who are at high risk, including those with compromised immune systems such as those living with HIV. The reason this specific regimen is endorsed is due to its efficacy in treating latent tuberculosis infection (LTBI), which can be particularly dangerous for people with HIV because their immunocompromised status increases the risk of progression from LTBI to active TB disease. Prophylactic treatment with INH significantly reduces this risk. In contrast to other options, INH is well-established and widely used for LTBI management. The duration of 9 months has been shown to balance effectiveness while minimizing side effects, making it a standard recommendation. Choosing other agents like Rifampin or Pyrazinamide does not align with the specific guidelines for latent TB treatment in HIV-infected individuals. Rifampin is typically used for active TB treatment and not specifically for LTBI in this scenario, while Pyrazinamide is part