How much isoniazid is needed for prevention of tuberculosis among immunocompetent adults?

Int J Tuberc Lung Dis. 1999 Oct;3(10):847-50.


Recommendations regarding how long isoniazid should be taken to prevent tuberculosis have gradually shifted from 12 to 6 months of treatment. These recommendations and the relevant evidence from controlled trials on duration of treatment are reviewed. The conclusions for immunocompetent adults are: 1) 6 months of preventive treatment does not give optimal protection; 2) more than 12 months of preventive treatment is not necessary; 3) 9-10 months appears to be the optimal duration; and 4) total duration of preventive treatment may be more important than its continuity.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Adult
  • Antitubercular Agents / administration & dosage*
  • Clinical Trials as Topic
  • Humans
  • Immunocompetence*
  • Isoniazid / administration & dosage*
  • Time Factors
  • Tuberculosis, Pulmonary / immunology
  • Tuberculosis, Pulmonary / prevention & control*


  • Antitubercular Agents
  • Isoniazid