What are the new CDC guidelines for treating tuberculosis?

New CDC Guidelines for Treating Tuberculosis

The 2020 CDC guidelines for treating tuberculosis recommend three preferred rifamycin-based regimens for latent TB infection (LTBI): 3 months of once-weekly isoniazid plus rifapentine, 4 months of daily rifampin, or 3 months of daily isoniazid plus rifampin. 1

Drug-Susceptible TB Treatment

First-Line Treatment Regimen

• For drug-susceptible TB, the standard 6-month regimen consists of:
  • Initial phase (2 months): Isoniazid, rifampin, pyrazinamide, and ethambutol daily
  • Continuation phase (4 months): Isoniazid and rifampin daily 2, 3
• Daily dosing is strongly recommended over intermittent dosing 1
• Dosing recommendations:
  • Adults: Isoniazid 5 mg/kg (up to 300 mg) daily; Rifampin 10 mg/kg (up to 600 mg) daily 4, 3
  • Children: Isoniazid 10-15 mg/kg (up to 300 mg) daily; Rifampin 10-20 mg/kg (up to 600 mg) daily 4, 3

Directly Observed Therapy (DOT)

• DOT is recommended for all patients with TB to ensure adherence 1
• Video-observed therapy (VOT) may be considered as an alternative to in-person DOT 1

Drug-Resistant TB Treatment

Isoniazid-Resistant TB

• Add a later-generation fluoroquinolone to a 6-month regimen of daily rifampin, ethambutol, and pyrazinamide 1
• Pyrazinamide duration may be shortened to 2 months in cases of noncavitary disease or toxicity 1

Multidrug-Resistant TB (MDR-TB)

• An all-oral regimen is now recommended instead of injectable-containing regimens 1
• Treatment should include at least 5 effective drugs based on susceptibility testing 1
• Treatment duration should be 15-21 months after culture conversion 1
• Consultation with a TB expert is essential for MDR-TB cases 1, 5

Special Populations

HIV Co-infection

• Same drug regimens as non-HIV patients, but careful attention to drug interactions between rifampin and antiretroviral medications 1
• For patients with CD4 count <100/μL, the continuation phase should be daily or three times weekly isoniazid and rifampin 1
• Extended treatment may be considered in cases of slow response to therapy 1

Pregnant Women

• Streptomycin should be avoided due to risk of congenital deafness 3
• Pyrazinamide is generally not recommended in the US due to inadequate teratogenicity data 3
• Initial treatment should consist of isoniazid and rifampin, with ethambutol added unless primary isoniazid resistance is unlikely 3

Children

• Similar regimens to adults with appropriate weight-based dosing 3
• Ethambutol should be used with caution in children whose visual acuity cannot be monitored 3

Latent TB Infection (LTBI) Treatment

The CDC now recommends three preferred rifamycin-based regimens for LTBI 1:

1. 3 months of once-weekly isoniazid plus rifapentine
2. 4 months of daily rifampin
3. 3 months of daily isoniazid plus rifampin

Alternative regimens include:

• 6 or 9 months of daily isoniazid 1

Monitoring and Follow-up

• Regular clinical evaluations to monitor for adverse effects, including hepatotoxicity, optic neuritis, and peripheral neuropathy 1
• Bacteriologic monitoring with sputum cultures to assess treatment response 1
• Treatment should be extended if the patient remains culture-positive after the initial phase 3

Common Pitfalls and Caveats

• Rifampin and rifapentine are not interchangeable; confusion between these drugs can lead to dosing errors 1
• A major cause of drug-resistant TB is patient non-adherence to treatment 3
• Failure to ensure susceptibility testing before initiating treatment can lead to ineffective regimens and development of additional resistance 1
• Inadequate monitoring for adverse effects can lead to unnecessary treatment discontinuation or serious complications 1

The CDC guidelines emphasize that only drugs to which the patient's M. tuberculosis isolate has documented or high likelihood of susceptibility should be included in the treatment regimen 1. With proper treatment and adherence, cure rates exceeding 95% can be achieved for drug-susceptible TB 1.