RESUMO
PURPOSE: Tumor necrosis factor (TNF) blockers increase the risk of tuberculosis infection. National recommendations in France for prevention of latent tuberculosis recommend treatment by rifampicin (RIF) 600 mg/day and isoniazid (INH) 300 mg/day for 3 months. However, its toxicity is unknown in this context and is a subject of debate. OBJECTIVE: To assess (a) frequency of prescription, (b) reasons for prescription, (c) tolerance of INH/RIF for prevention of tuberculosis. METHODS: Systematic retrospective study of medical records of one tertiary rheumatology unit, from 2002 to 2007, of all patients who were prescribed INH/RIF before receiving TNF blockers. DATA COLLECTION: patients'demographic characteristics, reasons of prescription, tolerance and levels of aminotransferase before and during INH/RIF treatment. ANALYSIS: Descriptive and determination of risk factors of hepatotoxicity by multivariate logistic regression. RESULTS: Of 1028 patients treated by TNF blockers between 2002 and 2007, 216 (21.1%) received INH/RIF treatment. Of 93 patients with complete data, 17 (18.2%) presented hepatotoxicity of which only one above 10 times the upper limit of the norm. Fourteen (15.0%) had other side effects. Ten (10.7%) patients had to interrupt INH/RIF for intolerance. Factors predicting intolerance were male sex, aminotransferases before treatment, a higher body mass index and leflunomide comedication. CONCLUSION: This systematic case review indicates a high rate of necessity for preventive treatment by INH/RIF, and in particular for positive skin tests. This association had a high rate of hepatotoxicity without severe consequences. A better screening of patients before preventive therapy is needed.