Treatment for TB Disease
When TB bacteria become active (multiplying in the body) and the immune system can t stop the bacteria from growing, this is called TB disease. TB disease will make a person sick. People with TB disease may spread the bacteria to people with whom they spend many hours.
It is very important that people who have TB disease are treated, finish the medicine, and take the drugs exactly as prescribed. If they stop taking the drugs too soon, they can become sick again; if they do not take the drugs correctly, the TB bacteria that are still alive may become resistant to those drugs. TB that is resistant to drugs is harder and more expensive to treat.
TB disease can be treated by taking several drugs for 6 to 9 months. There are 10 drugs currently approved by the U.S. Food and Drug Administration (FDA) for treating TB. Of the approved drugs, the first-line anti-TB agents that form the core of treatment regimens are:
- isoniazid (INH)
- rifampin (RIF)
- ethambutol (EMB)
- pyrazinamide (PZA)
TB Regimens for Drug-Susceptible TB
Regimens for treating TB disease have an intensive phase of 2 months, followed by a continuation phase of either 4 or 7 months (total of 6 to 9 months for treatment).
Drug Susceptible TB Disease Treatment Regimens
Twice weekly for 36 doses (18 weeks)
Do not use twice-weekly regimens in HIV-infected patients or patients with smear positive and/or cavitary disease. If doses are missed then therapy is equivalent to once weekly, which is inferior.
Abbreviations: DOT = directly observed therapy; EMB = ethambutol; HIV = human immunodeficiency virus; INH = isoniazid; PZA = pyrazinamide; RIF = rifampin.
a Other combinations may be appropriate in certain circumstances; additional details are provided in the Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis .
b When DOT is used, drugs may be given 5 days per week and the necessary number of doses adjusted accordingly. Although there are no studies that compare 5 with 7 daily doses, extensive experience indicates this would be an effective practice. DOT should be used when drugs are administered less than 7 days per week.
c Based on expert opinion, patients with cavitation on initial chest radiograph and positive cultures at completion of 2 months of therapy should receive a 7-month (31-week) continuation phase.
d Pyridoxine (vitamin B6), 25 50 mg/day, is given with INH to all persons at risk of neuropathy (e.g. pregnant women; breastfeeding infants; persons with HIV; patients with diabetes, alcoholism, malnutrition, or chronic renal failure; or patients with advanced age). For patients with peripheral neuropathy, experts recommend increasing pyridoxine dose to 100 mg/day.
e Alternatively, some U.S. TB control programs have administered intensive-phase regimens 5 days per week for 15 doses (3 weeks), then twice weekly for 12 doses.
Note: Use of once-weekly therapy with INH 900 mg and rifapentine 600 mg in the continuation phase is not generally recommended. In uncommon situations where more than once-weekly DOT is difficult to achieve, once-weekly continuation phase therapy with INH 900 mg plus rifapentine 600 mg may be considered for use only in HIV uninfected persons without cavitation on chest radiography.
Continuation Phase of Treatment
The continuation phase of treatment is given for either 4 or 7 months. The 4-month continuation phase should be used in most patients. The 7-month continuation phase is recommended only for the following groups:
- Patients with cavitary pulmonary TB caused by drug-susceptible organisms and whose sputum culture obtained at the time of completion of 2 months of treatment is positive;
- Patients whose intensive phase of treatment did not include PZA;
- Patients with HIV who are not receiving antiretroviral treatment (ART) during TB treatment; and
- Patients being treated with once weekly INH and rifapentine and whose sputum culture obtained at the time of completion of the intensive phase is positive.
(Note:Use of once-weekly therapy with INH 900 mg and rifapentine 600 mg in the continuation phase is not generally recommended. In uncommon situations where more than once-weekly DOT is difficult to achieve, once-weekly continuation phase therapy with INH 900 mg plus rifapentine 600 mg may be considered for use only in HIV uninfected persons without cavitation on chest radiography.)
Treatment completion is determined by the number of doses ingested over a given period of time.
Treatment for Drug-Resistant TB
Drug-resistant TB is caused by TB bacteria that are resistant to at least one first-line anti-TB drug. Multidrug-resistant TB (MDR TB) is resistant to more than one anti-TB drug and at least isoniazid (INH) and rifampin (RIF).
Extensively drug-resistant TB (XDR TB) is a rare type of MDR TB that is resistant to isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second-line drugs (i.e. amikacin, kanamycin, or capreomycin).
Treating and curing drug-resistant TB is complicated. Inappropriate management can have life-threatening results. Drug-resistant TB should be managed by or in close consultation with an expert in the disease.
For more information on drug-resistant TB, visit the Drug-Resistant TB Page