Clinical evaluation of the nelfinavir-rifabutin interaction in patients with tuberculosis and human immunodeficiency virus infection.

Study Objective: To characterize the bidirectional interaction between twice-daily nelfinavir and twice-weekly rifabutin and isoniazid in patients with tuberculosis and human immunodeficiency virus (HIV) infection.

Design: Prospective cohort study.

Setting: Three clinical research centers.

Association between acquired rifamycin resistance and the pharmacokinetics of rifabutin and isoniazid among patients with HIV and tuberculosis.

Background: The occurrence of acquired rifamycin resistance despite use of directly observed therapy for tuberculosis is associated with advanced human immunodeficiency virus (HIV) disease and highly intermittent administration of antituberculosis drugs. Beyond these associations, the pathogenesis of acquired rifamycin resistance is unknown.

Methods: We performed a pharmacokinetic substudy of patients in a trial of treatment with twice-weekly rifabutin and isoniazid.