Chapter 15 - Application of In Silico Drug Repurposing in Infectious Diseases

Abstract

Drug discovery is one of the most expensive and time-consuming processes in medical health science, and it appears that no new medication is in process for an infectious disease, which is increasing the “innovation gap” for pharmaceutical companies. After successful new indications of some old therapeutics, the term “drug repurposing” is more commonly discussed among the pharmaceutical companies as an approach to reduce the overall cost of producing new medicines and supports the companies to generate additional revenues. Initially, this attractive strategy was in practice in the large pharmaceutical companies as they hold the most well-known and abundant chemical-compound repositories; however, after domain databases like DrugBank were made available for public access, academics also join hands to utilize this approach to benefit society by developing drugs against infectious diseases/rare diseases, as established companies avoid investing in these diseases. 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 usage for existing drugs for infectious and neglected diseases. Several in silico-based methods are available to analyze the vast amount of medical data and come up with unique targets that can be further used for the drug-designing process. For structure-based drug-repurposing process, selectivity is a major concern and needs to be addressed at the initial stage to avoid the rejection of the drug later. In the present chapter we shall discuss the opportunities to achieve selectivity using computational pipeline in the repurposing strategy as applied to, especially, infectious diseases. In addition, we shall outline other methods that can be used for identifying new drug targets for these diseases.