Toward a More accurate, Evidence-Based Classification of CYP Inhibitors: A Critical Appraisal of Current Systems.

In this issue of CPT, Malavé et al. deliver a comprehensive reassessment of CYP2C19 inhibitor classifications through a systematic review of clinical drug-drug interaction (DDI) studies. While their findings bring clarity to specific discrepancies, this commentary explores the origins of such inconsistencies, particularly focusing on methodological, pharmacogenetic, and substrate-specific complexities. These issues prompt renewed consideration of how CYP inhibitor categories are defined, communicated, and used in clinical and regulatory settings.