Isoniazid for Preventing Tuberculosis in Non-HIV Infected Persons

Eleven trials involving 73,375 patients were included in a Cochrane review [Abstract] 1. Trials were generally of good quality. Treatment with INH resulted in a relative risk of developing active tuberculosis of 0.40 (95% CI 0.31 to 0.52), over two years or longer. There was no significant difference between 6 and 12 month courses (RR of 0.44 for six months, and 0.38 for 12 months). Preventive therapy reduced deaths from tuberculosis, but this effect was not seen for all cause mortality. INH was associated with hepatotoxicity in 0.36% of people on 6 months treatment and in 0.52% of people treated for 12 months.

The following decision support rules contain links to this evidence summary:

• INH prophylaxis for household contacts of a person with sputum smear-positive tuberculosis http://www.ebmeds.org/ebmeds/ebmeds_home.asp?mode=scripts&submode=view&id=scr00496&country=UK

References

• Smieja MJ, Marchetti CA, Cook DJ, Smaill FM. Isoniazid for preventing tuberculosis in non-HIV infected persons. Cochrane Database Syst Rev. 1999;(1):CD001363.