Post-translational modifications (PTMs) are critical regulators of protein stability, localization, and function and have been increasingly implicated in shaping drug responses across diverse diseases. While numerous studies have reported PTM-related mechanisms of drug sensitivity or resistance, no resource has systematically catalogued these associations in disease-specific contexts. Here, we present protein modification and drug sensitivity (PMADS), an integrated database that systematically organizes PTM-drug-disease ternary associations, defined as PTM-centered drug responses in disease context. PMADS catalogues over 4700 curated associations manually extracted from biomedical literature and over 43 800 predicted associations derived from analysis of large-scale proteomics datasets. Together, PMADS covers >6000 proteins, 1000 drugs, 19 types of PTMs, and 300 disease classes. The database emphasizes both upstream regulatory mechanisms, such as drug-induced modulation of PTMs, and downstream effects, such as PTM-mediated changes in drug sensitivity. Each entry includes detailed annotations such as PTM site, effect description, ternary diagram, supporting evidence, confidence score, and cross-references to external databases, including PDB, PhosphoSitePlus, and DrugBank. PMADS features a user-friendly web interface with advanced search, interactive visualizations, and structured data export to support research in pharmacology, functional genomics, and precision medicine. PMADS is freely available at https://pmads-db.org.
© The Author(s) 2025. Published by Oxford University Press.