Use of Allopurinol with Low-Dose 6-Mercaptopurine in Inflammatory Bowel Disease to Achieve Optimal Active Metabolite Levels: A Review of Four Cases and the Literature

Abstract

BACKGROUND: At least one-third of patients with inflammatory bowel disease do not respond or are intolerant to therapy with 6-mercaptopurine (6-MP). A subgroup fails to attain optimal levels of 6-thioguanine nucleotide (6-TGN) and instead shunts to 6-methylmercaptopurine nucleotide (6-MMPN).