RIFAMPIN PREVENTIVE THERAPY FOR TUBERCULOSIS INFECTION - EXPERIENCE WITH 157 ADOLESCENTS

For persons infected with Mycobacterium tuberculosis resistant to ison iazid (INH), rifampin is recommended for the prevention of active dise ase. However, the adverse effects and acceptability of this preventive therapy are largely uncharacterized. We prospectively followed 157 hi gh-school students exposed to, and probably infected with, M. tubercul osis strains resistant to INH. All 157 students were prescribed preven tive therapy with rifampin (10 mg/kg up to 600 mg daily) for 24 wk. Wh ile receiving therapy, 41 (26%) reported one or more adverse effects; of these, 18 had therapy interrupted temporarily, two permanently. Fou r (2.5%) had alanine aminotransferase elevations greater than two time s the upper limit of normal (range, 91 to 161 U/L); of these, one had therapy permanently stopped. Six (3.8%) self-discontinued therapy. No student was found to have active disease during the 2 yr of the study (exact 95% upper confidence limit, 2.2). We assumed that without preve ntive therapy, seven cases of tuberculosis would have occurred during these 2 yr. Therefore, we estimated that rifampin had a minimum protec tive effect of 56%. In conclusion, preventive therapy with rifampin wa s well tolerated and well accepted, and it appears effective in preven ting active tuberculosis.