What is the recommended treatment regimen for pulmonary tuberculosis (TB)?

Treatment of Pulmonary Tuberculosis

The recommended treatment regimen for drug-susceptible pulmonary tuberculosis consists of a two-month initial phase of isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), and ethambutol (EMB), followed by a four-month continuation phase of INH and RIF. 1

Initial Phase Treatment (First 2 Months)

• The standard four-drug regimen (INH, RIF, PZA, EMB) should be initiated for all patients with suspected or confirmed pulmonary TB until drug susceptibility results are available 1
• EMB may be discontinued once susceptibility to INH and RIF is confirmed 1
• The initial phase may be administered using one of the following schedules:
  • Daily dosing for 8 weeks (preferred) 1
  • Daily dosing for 2 weeks followed by twice-weekly dosing for 6 weeks 1
  • Three times weekly dosing throughout (only in select cases) 1

Continuation Phase Treatment (Next 4 Months)

• Standard continuation consists of INH and RIF for 4 months 1
• Administration options include:
  • Daily dosing (preferred) 1
  • Twice-weekly dosing under directly observed therapy (DOT) 1
  • Three times weekly dosing under DOT 1

Extended Treatment Duration Requirements

• A 7-month continuation phase (total 9 months of treatment) is recommended for patients with: 1
  • Cavitary pulmonary TB with positive sputum cultures after 2 months of treatment
  • Initial treatment that did not include PZA
  • Treatment with once-weekly INH and rifapentine with positive cultures after the initial phase

Administration Considerations

• Directly observed therapy (DOT) is strongly suggested over self-administered therapy for all TB patients 1
• When using DOT, medications may be given 5 days per week with the number of doses adjusted accordingly 1
• Pyridoxine (vitamin B6, 25-50 mg/day) should be given with INH to patients at risk of neuropathy (pregnant women, HIV-infected persons, diabetics, alcoholics, malnourished, chronic renal failure patients, or elderly) 1

Special Populations Considerations

• For HIV-infected patients with TB:
  • HIV testing should be performed for all TB patients 1
  • Avoid twice-weekly regimens in HIV-infected patients with CD4+ counts <100 cells/mm³ 1
  • Daily therapy is recommended during the intensive phase and at least three times weekly during the continuation phase 1

Monitoring Response to Treatment

• Clinical and laboratory monitoring should be performed regularly 1
• Patients should be educated about medication side effects and advised to seek immediate medical attention if they occur 1
• Baseline laboratory testing is indicated for patients with:
  • HIV infection
  • Suspected liver disorders
  • Pregnancy or immediate postpartum period
  • History of chronic liver disease
  • Regular alcohol use 1

Common Pitfalls to Avoid

• Never add a single drug to a failing regimen as this can lead to drug resistance 1
• Do not use twice-weekly regimens in patients with HIV infection or cavitary disease as missed doses can lead to treatment failure and acquired resistance 1
• Do not discontinue EMB too early if drug susceptibility results are unknown, especially in areas with high INH resistance rates 1
• Avoid streptomycin due to increasing global resistance unless susceptibility is confirmed 1