Follow-up results of isoniazid chemoprophylaxis during biological therapy in Colombia.

The use of biological therapy has been linked with an increased risk of tuberculosis (TB) reactivation. The aim of this study was to present the follow-up results for isoniazid (INH) chemoprophylaxis in patients receiving different biological therapies. In this prospective observational study, patients with latent tuberculosis infection (LTBI) were given INH chemoprophylaxis between 2 and 9 months prior to the beginning of biological therapy. All patients were followed up monthly for any signs or symptoms of active TB or INH toxicity. A total of 221 patients, 122 females (55.2 %), with a mean age of 46.8 ± 11.3 years (16-74) were enrolled. LTBI was identified in 218 patients (98.7 %), all of whom received INH chemoprophylaxis. Seven patients (3.2 %) developed active tuberculosis, and 32 (17.2 %) patients developed intolerance or toxicity related to INH. Chemoprophylaxis with INH seems to be effective and safe for the prevention of most TB reactivation in individuals with LTBI, but toxicity must be monitored during follow-up.