From the Guidelines
For unconfirmed tuberculosis (TB) treatment, empiric therapy should be initiated with isoniazid, rifampin, pyrazinamide, and ethambutol for the initial 2 months, followed by isoniazid and rifampin for an additional 4 months, as this approach is supported by the most recent and highest quality evidence 1.
Key Considerations
- The standard first-line regimen consists of isoniazid (INH) 5 mg/kg daily (maximum 300 mg), rifampin (RIF) 10 mg/kg daily (maximum 600 mg), ethambutol (EMB) 15-25 mg/kg daily, and pyrazinamide (PZA) 15-30 mg/kg daily for the first 2 months (intensive phase) 1.
- The continuation phase should consist of INH and RIF for an additional 4 months, for a minimum total treatment period of 6 months 1.
- Patients with cavitary pulmonary TB disease and positive cultures of sputum specimens at the completion of 2 months of therapy should receive a longer, 7-month continuation phase of therapy (total duration: 9 months) 1.
- Directly observed therapy (DOT) is recommended to ensure adherence, and liver function tests, visual acuity (with ethambutol), and clinical monitoring should be performed regularly 1.
Patient Evaluation and Monitoring
- Patients suspected of having current TB disease should immediately be started on appropriate treatment, ideally with directly observed therapy (DOT), and placed in TB isolation as necessary 1.
- Patients with TB and unknown HIV-infection status should be counseled and offered HIV testing, and HIV-infected patients undergoing treatment for TB should be evaluated for antiretroviral therapy 1.
- Routine measurements of hepatic and renal function and platelet count are not necessary during treatment unless patients have baseline abnormalities or are at increased risk of hepatotoxicity 1.
From the Research
Unconfirmed TB Treatment
- The standard treatment for active or suspected tuberculosis should include isoniazid, rifampin, pyrazinamide, and ethambutol until susceptibility is known 2.
- For patients with drug-susceptible pulmonary tuberculosis, the continuation phase of treatment should be a combination of isoniazid and either rifampin or rifapentine, taken for 4 or 7 months depending on risk factors 2.
- Treatment of latent tuberculosis infection is an important component of TB control programs, and preventive treatment can reduce the risk of developing active TB 3.
- The standard treatment consists of a combination of isoniazid, rifampicin, ethambutol, and pyrazinamide, followed by a combination of isoniazid and rifampicin only 4.
- In cases of isoniazid-resistant tuberculosis, a regimen of isoniazid, rifampin, pyrazinamide, and ethambutol given daily for 6 months has been shown to produce successful outcomes 5.
- The major cause of therapeutic failure is noncompliance of the patient in taking the medication regularly, and the second major cause of treatment failure is resistance of tubercle bacilli to the antimicrobial agents used 6.
Treatment Considerations
- Directly observed therapy by a healthcare worker should be offered to all patients with active tuberculosis to minimize treatment failure, relapse, and the emergence of drug resistance 2.
- Liver damage is one of the more common adverse effects of TB treatment, arising in 2.4% of patients 4.
- Multidrug-resistant tuberculosis should be treated with directly observed therapy in collaboration with a clinician familiar with management of these conditions, and treatment must include at least 4 drugs to which the organism is susceptible 2.