Drug repositioning: re-investigating existing drugs for new therapeutic indications.

Drug discovery and development is an expensive, time-consuming, and risky enterprise. In order to accelerate the drug development process with reduced risk of failure and relatively lower costs, pharmaceutical companies have adopted drug repositioning as an alternative. This strategy involves exploration of drugs that have already been approved for treatment of other diseases and/or whose targets have already been discovered. Various techniques including data mining, bioinformatics, and usage of novel screening platforms have been used for identification and screening of potential repositioning candidates. However, challenges in clinical trials and intellectual property issues may be encountered during the repositioning process. Nevertheless, such initiatives not only add value to the portfolio of pharmaceutical companies but also provide an opportunity for academia and government laboratories to develop new and innovative uses of existing drugs for infectious and neglected diseases, especially in emerging countries like India.