Drug Repurposing: Expanding Therapeutic Potential of Existing Drugs

Abstract

Drug repositioning or drug repurposing is the process of finding new indications for existing drugs.
More recently, the use of drugs already approved for other indications has become of great interest as
an alternative to de novo drug discovery as it involves a shorter development time, lower development
cost and reduced risk of development, while the drugs are already approved and have known safety and
pharmacokinetic profiles. This review summarizes the origins, development and importance of drug
repurposing, as well as its benefits over the traditional drug development process. The following drug
repurposing strategies are introduced, such as the drug-centric, target-centric, disease-centric,
experimental, computational and network pharmacology approaches. The contribution of
pharmaceutical science to drug repurposing via formulation development, Pharmacological Evaluation,
Medicinal Chemistry, and Biotechnology and Natural Products also is reviewed. In addition, the review
highlights the current clinical uses of drug repositioning in the fields of oncology, cardiovascular
diseases, neurological disorders, infectious diseases and metabolic disorders. Examples of successful
drugs that have been repurposed include sildenafil, thalidomide, minoxidil, metformin and aspirin. The
drug repurposing opportunities and challenges with regulatory considerations and patent issues are also
explored. In conclusion, drug repurposing is a potentially valuable and low-cost approach to speeding
up drug development, filling unmet medical demands, and enhancing therapeutic results.