Pharmacokinetics of IFX and TNF Concentrations in Serum, Stool, and Colonic Mucosa in Acute Severe Ulcerative Colitis

In Acute Severe Ulcerative Colitis (ASUC), drug exposure may be affected by intestinal protein loss leading to hypoalbuminemia and rapid clearance of infliximab (IFX). Importantly, 2 studies have associated the loss of IFX in stool with poor outcomes. Multiple observational studies have identified that patients with faster IFX clearance have worse clinical outcomes and higher rates of antidrug antibody formation. To better understand optimal dosing of IFX in ASUC, the pharmacokinetics of IFX in association with outcomes must be better defined in this setting.