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U.S. Department of Health and Human Services


Core Curriculum on Tuberculosis, 2000

Chapter 6
Treatment of Latent TB Infection (LTBI)

Updated August 2003

(See Tables 1 and 2)

There are several treatment regimens available for the treatment of LTBI, and providers should discuss options with their patients. For persons who are at especially high risk for TB and are either suspected of nonadherence or are on an intermittent dosing regimen, directly observed therapy (DOT) of LTBI should be considered. This method of treatment is especially appropriate when a household member is on DOT for active disease, or in institutions and facilities where treatment for infection can be observed by a staff member.

In clinical trials, daily isoniazid treatment for latent infection for 12 months reduced the risk for TB disease by more than 90% in patients who completed a full course of therapy. 1 There is evidence that 6 months of treatment for LTBI with isoniazid can also confer a high degree of protection (approximately 70% in patients who complete the regimen) against the progression of TB infection to TB disease. 1 The protection conferred by taking at least 9 months of isoniazid is greater than that conferred by taking 6 months.

Isoniazid is normally used alone for treatment of LTBI in a single daily dose of 300 mg in adults and 10-15 mg/kg body weight in children, not to exceed 300 mg per dose. Isoniazid can be given two times a week at a dosage of 15 mg/kg as DOT of LTBI. 2,3  When isoniazid is given alone to persons with active TB disease, resistance to isoniazid is likely to develop. For this reason, persons suspected of having TB disease should receive the recommended multidrug regimen for treatment of disease until the diagnosis is confirmed or ruled out.

A 9-month regimen (minimum of 270 doses administered within 12 months) is considered optimal treatment for both HIV-positive and HIV-negative adults. A 6-month regimen (minimum of 180 doses administered within 9 months) may also provide sufficient protection. HIV-positive and HIV-negative children should receive 9 months of isoniazid treatment for infection. Twice-weekly regimens should consist of at least 76 doses administered within 12 months for the 9-month regimen and 52 doses within 9 months for the 6-month regimen. Treatment for LTBI for 6 months rather than 9 months may be more cost-effective and result in greater adherence by patients, therefore, local programs may prefer to implement the 6-month regimen rather then the 9-month regimen. Every effort should be made to ensure that patients adhere to treatment for infection for at least 6 months.

Peripheral neuropathy is associated with the use of isoniazid but is uncommon at doses of 5 mg/kg. Persons with conditions in which neuropathy is common (e.g., diabetes, uremia, alcoholism, malnutrition, HIV-infection), as well as pregnant women and persons with a seizure disorder, may be given pyridoxine (vitamin B6) (10-50 mg/day) with isoniazid.

Four months of daily rifampin (minimum of 120 doses administered within 6 months) is an acceptable alternative to the longer regimens of isoniazid alone.

Due to the reports of severe liver injury and deaths, CDC advises that the use of the combination of Rifampin (RIF) and pyrazinamide (PZA) for the treatment of LTBI should generally not be offered for either HIV-negative or HIV-infected persons. If the potential benefits significantly outweigh the demonstrated risk of severe liver injury and death associated with this regimen and the patient has no contraindications, a TB/LTBI expert should be consulted prior to the use of this regimen.8


Released October 2008
Centers for Disease Control and Prevention
National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention
Division of Tuberculosis Elimination -

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