An overview to drug repurposing.

Identification and implementation of novel drug are not only time consuming and expensive but also it poses huge challenge to reach into the market. Currently, thousands of USFDA approved drugs licence are being expired that can be repurposed for treating other diseases. Drug repurposing is an alternative solution to reduce time, cost and steps for development of drugs and their applications for treating disease. The current chapter emphases to brief the steps involved in drug discovery and drug repurposing. The chapter also includes repurposed drugs for treating bacterial, fungal and viral diseases. Unlocking the potential of already existed drug and repurposing them for other diseases that could accelerate drug discovery and aid in managing outbreaks.