Contemporary Trends in Drug Repurposing: Identifying New Targets for Existing Drugs

Drug repurposing or drug repositioning has emerged as an efficient, very popular and alternative technique in modern drug discovery to identify old drugs for new targets cost-effectively and dynamically. This concept gets a tremendous boost, especially in the century's most challenging healthcare concern of the Covid-19 pandemic across the globe. In this approach, scientists seek new indications and clinical use of the drugs at minimum risk, which have previously already been pharmacologically established and approved. The methods developed for drug repositioning include computational approaches and biological methodologies, and with the fast technological advancement, various new drug-target- diseases are discovered, and thereby immense information is now available in the different databases, such as DrugBank, OMIM, ChemBank, KEGG, Pubmed, Genecard, and many more. The information available on all the above public domain databases has been utilized successfully in many drug repositioning projects. The present chapter discusses the concept of drug repurposing and its impact on academia, industries and, of course, their social implications. Besides this, the chapter will also cover details on tools and techniques to identify drugs for repositioning and their application in identifying drugs for various diseases and disorders. The current work will also foresee the recent market analysis and updates on the cost of drug discovery and development by drug repurposing, its comparison with traditional drug discovery approaches, challenges involved with drug repurposing, and future perspectives. 

Keywords: Case studies, Drug repositioning, Drug repurposing, in silico approaches, Polypharmacology, Pharmacological approaches.