What is the treatment for latent tuberculosis (TB)?

From the Guidelines

Treatment for latent tuberculosis infection (LTBI) should involve a course of antibiotics, with the recommended first-line regimen being isoniazid (INH) 300mg daily for 6-9 months, or alternative shorter regimens such as rifampin 600mg daily for 4 months, or a combination of isoniazid 300mg plus rifapentine 900mg once weekly for 12 weeks (known as 3HP), as outlined in the 2020 guidelines from the National Tuberculosis Controllers Association and CDC 1.

Key Considerations

• The choice of regimen should be based on patient factors, such as ability to tolerate the medication and potential for drug interactions.
• All patients should receive pyridoxine (vitamin B6) 25-50mg daily with isoniazid to prevent peripheral neuropathy.
• Before starting treatment, baseline liver function tests should be obtained, and patients should be monitored monthly for side effects such as hepatotoxicity, particularly those over 35 years old or with underlying liver disease.

Alternative Regimens

• A 3-month regimen of daily isoniazid 300mg plus rifampin 600mg is another option for those who cannot tolerate isoniazid.
• The 3HP regimen is also recommended for use in persons with LTBI aged 2–17 years, and in persons with LTBI who have HIV infection, including acquired immunodeficiency syndrome (AIDS), and are taking antiretroviral medications with acceptable drug-drug interactions with rifapentine, as outlined in the 2018 update from the CDC 1.

Importance of Treatment Completion

• Treatment completion is crucial for effectiveness, with completion rates being higher for shorter regimens.
• These medications work by killing dormant TB bacteria before they can reactivate and cause disease, reducing the risk of progression to active TB by 60-90%.
• Patients should avoid alcohol during treatment and report symptoms like persistent nausea, abdominal pain, or yellowing of the skin promptly.

From the FDA Drug Label

Tuberculosis Rifampin is indicated in the treatment of all forms of tuberculosis. A three-drug regimen consisting of rifampin, isoniazid, and pyrazinamide is recommended in the initial phase of short-course therapy which is usually continued for 2 months Following the initial phase, treatment should be continued with rifampin and isoniazid for at least 4 months

The treatment for latent TB is not explicitly mentioned in the provided text. However, based on the information provided for the treatment of tuberculosis, it can be inferred that rifampin may be used in combination with other drugs for the treatment of TB, but the specific treatment for latent TB is not directly addressed.

• The provided text discusses the treatment of active TB and the use of rifampin in combination with other drugs.
• It does not provide information on the treatment of latent TB. 2

From the Research

Treatment Options for Latent TB

• The treatment of latent tuberculosis infection (LTBI) is an essential component of TB control and elimination 3.
• Several treatment regimens are available, including:
  • Once-weekly isoniazid plus rifapentine for 3 months
  • Daily rifampin for 4 months
  • Daily isoniazid plus rifampin for 3-4 months
  • Daily isoniazid for 6-9 months

Efficacy and Safety of Treatment Regimens

• A 9-month regimen of isoniazid can prevent active tuberculosis in persons with latent tuberculosis infection, but it has been associated with poor adherence rates and toxic effects 4.
• A 4-month regimen of rifampin was found to be not inferior to a 9-month regimen of isoniazid for the prevention of active tuberculosis and was associated with a higher rate of treatment completion and better safety 4, 5.
• The rifampin-containing regimens are shorter and have similar efficacy, adequate safety, and higher treatment completion rates compared to isoniazid monotherapy 3.

Comparison of Treatment Regimens

• A study comparing 4 months of rifampin therapy with 9 months of isoniazid therapy for latent tuberculosis infection found that rifampin led to fewer serious adverse events and better adherence than isoniazid 5.
• Another study found that 3 months of rifampin had somewhat better efficacy than either 3 months of isoniazid and rifampin or 6 months isoniazid 6.

Ongoing Research and Future Directions

• Novel vaccine strategies, host immunity-directed therapies, and ultrashort antimicrobial regimens for TB prevention are under evaluation 3.
• Newer studies are investigating even shorter LTBI treatment with durations of less than 2 months 7.
• The first randomized trials for treating LTBI in contacts to MDR-TB are currently enrolling 7.