I swear this changes on who you ask. I've seen it as either Isoniazid or Isoniazid + rifampin.

EDIT: 2 answers are correct here (thanks NBME!)

Per CDC

"As of 2018, there are four CDC-recommended treatment regimens for latent TB infection that use isoniazid (INH), rifapentine (RPT), and/or rifampin (RIF). All the regimens are effective."

https://www.cdc.gov/tb/topic/treatment/decideltbi.htm#:~:text=As%20of%202018%2C%20there%20are,All%20the%20regimens%20are%20effective.

• Patient with a positive PPD (>10 mm in healthcare workers) who is asymptomatic and without CXR changes, most consistent with latent tuberculosis
• Key idea: 3 treatment options for latent tuberculosis are (1) Isoniazid and rifapentine weekly for 3 months (2) Isoniazid for 6-9 months (3) Rifampin for 4 months
• Key idea: PPD induration (NOT erythema) required for positivity depends upon patient risk factors with >5 mm being positive in patients with significant immunosuppression (HIV, organ transplant, immunosuppressant meds), recent contact with patient with active TB or patients with CXR findings consistent with TB // >10 mm being positive for patients from Tb endemic countries, IVDU, residents of high-risk settings (prisons, nursing homes, homeless shelters, etc.), children < 4 years old and patients working in mycobacterial labs // >15 mm in all patients

https://step-prep.org