Dose Regimen of Para-Aminosalicylic Acid Gastro-Resistant Formulation (PAS-GR) in Multidrug-Resistant Tuberculosis

Background and Objectives Resurgence of multidrug-resistant tuberculosis (MDR-TB) has raised a renewed interest in para-aminosalicylic acid (PAS) and other efficacious drugs. A gastro-resistant granule formulation (PAS-GR) was designed to be better tolerated than earlier forms of PAS, with fewer adverse effects from reduced production of meta-aminophenol. PAS release from PAS-GR granules is slower than with earlier formulations. Pharmacokinetic data are, however, limited and only a few studies have assisted in defining the best PAS-GR dose regimen. Interest in refining the latter continues and recent data contributed in better defining the optimal PAS-GR dose regimen in adults and children. The present paper draws on these recent studies, synthesizes pharmacokinetic results from different population groups, and draws comparisons with in vitro data and the results of earlier pharmacokinetic studies in order to discuss the most appropriate dosing regimen for PAS-GR.