CLINICAL THERAPEUTICS AND HEMATOLOGIC COMPLICATIONS: Edited by W. Joseph McCuneThe use of mycophenolate mofetil area under the curveChakrabarti, Katherinea; Frame, Davidb; Al Abbas, Mousac; McCune, W. JosephaAuthor Information aDepartment of Internal Medicine, Division of Rheumatology, University of Michigan bDepartment of Clinical Pharmacy, University of Michigan, Ann Arbor, Michigan, USA cStaff Rheumatologist, King Fahad Specialist Hospital, Dammam, Saudi Arabia Correspondence to W. Joseph McCune, Division of Rheumatology/Department of Internal Medicine, 300 North Ingalls St., Suite 7C27, Ann Arbor, Michigan 48109-5422, USA. Tel: +734 936 5561; e-mail: [email protected] Current Opinion in Rheumatology: May 2021 - Volume 33 - Issue 3 - p 221-232 doi: 10.1097/BOR.0000000000000799 Buy Metrics Abstract Purpose of review Although mycophenolate mofetil (MMF) has been used successfully to treat a myriad of autoimmune diseases, its complex pharmacokinetics make it difficult to determine the true drug exposure for an individual patient. This review summarizes the body of literature focused on the gold standard measurement of the area under the curve (AUC) of mycophenolic acid (MPA), the active metabolite of MMF. Recent findings Fixed dosing of MMF leads to highly variable drug exposure. Retrospective series have reported improved clinical outcomes when a minimum AUC value from 0 to 12 h (AUC0–12h) ≥30 mg h/l is achieved. MPA levels are affected by various drug interactions, hypoalbuminemia, and renal insufficiency and the measurement of free rather than total MPA levels is prudent in some situations. A limited number of studies employing prospective dose adjustment of MMF based on AUC0–12h measurements have yielded mixed results. Summary Given the wide range of MPA AUC encountered in autoimmune diseases, dose adjustments of MMF based on AUC rather than fixed dosing of MMF should be considered in both clinical practice and clinical trials. Limited sampling strategies have been proposed to improve clinical feasibility of measurements, but a standard is yet to be defined. Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.