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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


Before treatment for LTBI is started, clinicians should conduct a medical history to

  • Rule out the possibility of TB disease;

  • Determine the history of treatment for LTBI or disease;

  • Determine if there are any preexisting medical conditions that are a contraindication to treatment or are associated with an increased risk of adverse effects of treatment;

  • Obtain information about current and previous drug therapy, including any previous adverse reactions to drugs considered for treatment of LTBI and to current drugs which have known interactions with drugs used for the treatment of LTBI;

  • Recommend HIV testing if risk factors are present.

In addition, conducting a medical history provides an opportunity to establish rapport with the patient and to highlight important aspects of treatment, such as

  • Benefits of treatment 

  • Importance of adherence to the treatment regimen

  • Possible adverse side effects of the regimen

  • Establishment of an optimal follow-up plan

Baseline laboratory testing is not routinely indicated for all patients at the start of LTBI treatment. Baseline hepatic measurements of serum aminotransferases and bilirubin are indicated for patients whose initial evaluation suggests a liver disorder. Baseline testing is also indicated for patients with HIV infection, women who are pregnant or in the immediate postpartum period, persons with a history of liver disease (e.g., hepatitis B or C, alcoholic hepatitis or cirrhosis, persons who use alcohol regularly, and others who are at risk of chronic liver disease), persons who use alcohol regularly, and others who are at risk of chronic liver disease.

Baseline laboratory testing is not routinely indicated in older persons. However, testing may be considered on an individual basis, particularly for patients who are taking other medications for chronic medical conditions. Active hepatitis and end-stage liver disease are relative contraindications to the use of INH.

During treatment of LTBI, patients should be clinically evaluated at least once a month for:

  • Adherence to the prescribed regimen
  • Signs and symptoms of active TB disease
  • Signs and symptoms of hepatitis

Patients should be instructed to stop taking medication immediately and seek medical consultation if abdominal pain, emesis, jaundice, or other hepatitis symptoms develop.

Routine laboratory monitoring during treatment of LTBI with isoniazid or rifampin is indicated only for those whose baseline tests suggest a liver disorder and for other persons with a risk of hepatic disease or for patients with symptoms compatible with hepatotoxicity to allow for the evaluation of possible adverse reactions that might occur during treatment.

Some evidence suggests that women, particularly black and Hispanic women, are at increased risk for fatal hepatitis associated with isoniazid 7  This risk may also be increased during the postpartum period. These persons should be closely monitored for adverse reactions throughout the course of treatment.

About 10% to 20% of persons taking isoniazid will have some mild, asymptomatic elevation of serum aminotransferase. These abnormalities tend to resolve even if isoniazid is continued. If any of the measurements exceed three to five times the upper limit of normal or if the patient reports symptoms of adverse reactions, the discontinuation of isoniazid should be strongly considered.

CDC is collecting reports of severe liver injury (i.e., leading to hospital admission or death) in persons receiving any regimen for LTBI.  Report possible cases to the Division of Tuberculosis Elimination at (404) 639-8442.

e Division of Tuberculosis Elimination at (404) 639-8116.


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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