Recent advances in drug repositioning and rediscovery for different therapeutic activities utilizing updated technological approaches.

Traditional or de novo drug discovery is a time-consuming, costly, and high-investment process due to the high attrition rate. Therefore, many trials are conducted to reuse existing drugs to treat pressing conditions and diseases, since their safety profiles and pharmacokinetics are already available. Drug repurposing (DR) (also known as drug repositioning) is a strategy to identify a new indication of existing or already-approved drugs, beyond the scope of their original use. Various in silico-based computational and activity-based experimental approaches to incorporate available resources have been suggested for gaining a better understanding of disease mechanisms and the identification of repurposed drug candidates for personalized pharmacotherapy. This strategy is highly efficient, timesaving, low-cost, and minimum risk of failure. It maximizes the therapeutic value of a drug and consequently increases the success rate. This review introduced publicly available databases for drug repositioning and summarized the approaches taken for drug repositioning. Also, it highlighted and compared their characteristics, which should be addressed for the future realization of drug repositioning.