ColumnsDrug-Drug Interactions (DDIs) in Psychiatric Practice, Part 8 Relative Receptor Binding Affinity as a Way of Understanding the Differential Pharmacology of Currently Available AntidepressantsPRESKORN, SHELDON H. MDAuthor Information PRESKORN: Kansas University School of Medicine-Wichita, Wichita, KS This column has been adapted with permission from material in Preskorn SH. Drug-drug Interactions With an Emphasis on Psychiatric Medications, 1st ed. West Islip, NY, and Durant, OK: Professional Communications; 2018. To order a copy of the book, readers can call 1-800-337-9838 or visit the Professional Communications website at www.pcibooks.com. Over his 40-year career, S.H.P. has worked with over 140 pharmaceutical and biotech companies in the United States and throughout the world. Over the past year, he has received grants/research support from or has served as a consultant, on the advisory board, or on the speaker’s bureau for Alkermes, Allergan, Bionomics, BioXcel, Janssen, National Institute of Mental Health, Perception Neuroscience, and Sunovion. All clinical trial and study contracts were with and payments made to the Kansas University Medical Center Research Institute, a research institute affiliated with Kansas University School of Medicine-Wichita. Please send correspondence to: Sheldon H. Preskorn, MD, University of Kansas Medical Center, 1010 North Kansas, Wichita, KS 67217. Journal of Psychiatric Practice: January 2020 - Volume 26 - Issue 1 - p 46-51 doi: 10.1097/PRA.0000000000000445 Buy Metrics Abstract This column is the eighth in a series exploring drug-drug interactions (DDIs) with a special emphasis on psychiatric medications. The first 3 columns in this DDI series discussed why patients being treated with psychiatric medications are at increased risk for taking multiple medications and thus experiencing DDIs, how to recognize such DDIs, strategies for avoiding and/or minimizing adverse outcomes from such DDIs, and pharmacokinetic considerations concerning DDIs in psychiatric practice. The fourth and fifth columns in this series presented a pair of parallel tables, one of which outlined the primary, known mechanism(s) of action of all commonly used psychiatric medications and one of which summarized major types of pharmacodynamic DDIs based on mechanism of action. Clinicians can use these 2 tables together to predict pharmacodynamically mediated DDIs. The sixth column discussed key pharmacodynamic interactions involving ethanol, opioids, and monoamine oxidase inhibitors. That column focused particularly on hypertensive crises and serotonin syndrome with monoamine oxidase inhibitors and also DDIs involving psychiatric medications with adverse effects on the cardiovascular system and on the central nervous system. The seventh column presented the concept of relative receptor binding and included a table summarizing the relative receptor binding affinity of antipsychotics including all of the newer agents as well as some of the older agents such as haloperidol. This eighth column in this series presents a parallel table to the one in the seventh column summarizing the relative receptor binding affinity of currently available antidepressants. The overall goal of this series of columns is to present a simple way of conceptualizing neuropsychiatric medications in terms of their pharmacodynamics and pharmacokinetics to allow prescribers to take these facts into consideration when they need to use ≥2 drugs in combination to optimally treat a patient. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.