Unmasking a silent assault: Molecular mechanisms and clinical implications of fentanyl-induced cardiotoxicity

Background Fentanyl, an ultra-potent synthetic opioid, has revolutionized analgesia while contributing substantially to the modern opioid crisis. Beyond its well-known respiratory effects, accumulating evidence implicates fentanyl and its analogs in direct cardiovascular injury. Methods This review synthesizes mechanistic and translational data demonstrating that fentanyl-induced cardiotoxicity appears to be driven by oxidative stress, mitochondrial dysfunction, dysregulated calcium handling, and endothelial impairment. Advanced human models—particularly iPSC-derived cardiomyocytes and vascular organoids—have provided important insights into key signaling axes including Nrf2 suppression, CaMKII hyperactivation, maladaptive MAPK and NF-κB signaling, and disrupted mitophagy, which collectively promote cardiomyocyte apoptosis, arrhythmogenesis, myocardial fibrosis, and vascular inflammation. Results We discuss candidate biomarkers (oxidative stress markers, troponins, transcriptomic/proteomic signatures) and emerging therapeutic strategies aimed at mitochondrial protection, kinase modulation, and restoration of endothelial nitric oxide signaling. Conclusion Finally, we propose integrative research directions—multi-omics, patient-derived models, and precision toxicology—to enable earlier detection and targeted interventions. Recognizing fentanyl as a multifaceted cardiotoxin reframes clinical surveillance and suggests novel avenues for mitigation.