[Three-month course of rifampicin and isoniazid for the treatment of latent tuberculous infection]. / Pauta de tres meses de rifampicina e isoniacida para el tratamiento de la infección latente tuberculosa.

ABSTRACT

BACKGROUND AND OBJECTIVES: Isoniazid (I) is the drug of choice for treating latent tuberculous infection (LTI). Duration of treatment with I and its liver toxicity represent a serious drawback for a correct enforceability. In several clinical guides, a 3-month course with rifampicin (Rif) and I is recommended as an acceptable alternative to the 6-9 month course with I. Here we present our experience with this new regimen. PATIENTS AND METHODS: From 2001, the 3-month regimen with Rif and I was offered to patients older than 14 years, who were recruited in the contacts study. A good adherence was considered when the patient manifested so and he/she went to the scheduled monthly controls. We performed baseline liver analyses in those patients at risk of hepatotoxicity and in all patients older than 35 years. In all cases, a liver laboratory control was done at the first month of treatment and whenever patients had symptoms suggestive of intolerance. Databases of tuberculosis controls and contacts were crossed to evaluate the number of individuals who developed tuberculosis. RESULTS: Between 2000 and 2008, treatment for LTI was indicated in 547 contacts (7.8% refused treatment, 34.1% with the 6-month I course, 63.5% with the 3-month Rif and I course and 2.3% with other regimens). A total of 84.97% (147/173) patients with the 6-month I regimen and 92.55% (302/322) with the 3-month Rif and I course fulfilled the treatment (p=0.024). 2.37% (4/169) and 1.6% (5/313) patients with the 6-month I course and 3-month Rif and I course, respectively, withdrew because of hepatotoxicity (p=0.33). There were no patients among those who fulfilled the treatment in any of the 2 study arms. CONCLUSION: There was a higher adherence (statistically significant) and lower hepatotoxicity with the 3-month Rif and I regimen. Both regimens showed a full effectivity.