Drug Repurposing - Success Stories: A Narrative Review

Abstract:

Drug repurposing, or drug reprofiling or repositioning, refers to the use of an originally approved drug for new therapeutic indications. During the COVID-19 pandemic, it received massive attention as the healthcare system struggled to find an effective treatment. There are significant advantages of drug repurposing over traditional drug discovery, such as reduced development time, lower regulatory risk, lower costs, and completed safety profiles and pharmacokinetic studies. Drug repurposing involves computational and experimental approaches, which help identify candidate drugs, measure their performance in preclinical models, and progress to clinical trials in later stages. Its foundation is formed by public drug databases, clinical trial outcomes, use of off-label reports, primary and translational research data, and other published human studies. Novel therapeutics are uncovered by combining bioinformatics, molecular docking, genetic and phenotypic data, binding assays, pathway analysis, and methodically charting drug-target interactions through research. This narrative review article specifically addresses key literature gaps by contrasting genuine mechanistic repurposing against broad-spectrum label extensions. Furthermore, by incorporating recent clinical updates, evaluating neutral/failed translation attempts, and contextualizing repurposing within precision multi-omics and real-world evidence, this article provides a modernized framework for sustainable therapeutic innovation.