Old knowledge confirmed by new study.
[him] moderator
++++++++++++++++++++
TB Prophylaxis in HIV-Infected Adults
Summary and Comment
TB Prophylaxis in HIV-Infected Adults: Stick with the WHO Recommendations
In an open-label clinical trial, taking isoniazid alone for 6 months was
just as effective as taking it for longer or adding rifamycin.
Isoniazid is effective in preventing tuberculosis (TB) and is currently
recommended by the WHO (at a dose of 300 mg daily for 6 months) for all
HIV-infected individuals who have a positive tuberculin skin test or are
living in areas where skin testing is not feasible and the prevalence of
latent TB exceeds 30%. Unfortunately, isoniazid prophylaxis is not widely
used because of concerns about drug resistance, low adherence rates, and
the potential for reinfection.
In this open-label, randomized trial, researchers evaluated the efficacy of
three alternative TB prophylactic regimens relative to standard isoniazid
therapy. A total of 1148 HIV-infected adults in South Africa who had a
positive tuberculin skin test but were not yet on antiretroviral therapy
were randomized to receive one of the following: Rifapentine (900 mg) plus
isoniazid (900 mg) once weekly for 12 weeks Rifampin (600 mg) plus
isoniazid (900 mg) twice weekly for 12 weeks Isoniazid (300 mg) daily for
the duration of the study (<=6 years; continuous isoniazid) Isoniazid (300
mg) daily for 6 months (controls)
The overall incidence of TB was 1.9 cases per 100 person-years. The
incidence of TB or death (a composite endpoint) did not differ
significantly between any of the alternative-regimen groups and the control
group: 3.1 per 100 person-years in the rifapentine-isoniazid group, 2.9 in
the rifampin-isoniazid group, 2.7 in the continuous isoniazid group, and
3.6 in the control isoniazid group. The continuous isoniazid group (which
received the drug daily for a median of 3.3 years) had the highest rates of
serious adverse events and of both temporary and permanent treatment
discontinuation.
Comment: These findings suggest that the alternative prophylactic
treatments evaluated here achieve outcomes similar to those attained with
the standard, WHO-recommended 6-month course of isoniazid treatment. No
benefit is gained by taking isoniazid for more than 6 months or by adding
rifampin or rifapentine. The current WHO-recommended regimen is as
effective as (and cheaper than) longer isoniazid regimens or combination
treatments.
-- Salim S. Abdool Karim, MD, PhD
Published in Journal Watch HIV/AIDS Clinical Care July 11, 2011
Citation(s):
Martinson NA et al. New regimens to prevent tuberculosis in adults with HIV
infection. N Engl J Med 2011 Jul 7; 365:11. (Free)
