Drug Repositioning: A Review

Drug repositioning is one of the common strategies of new indications and therapeutic targets for already known drugs.  Drug repositioning is known by various names in textbooks such as drug re-proposing, re-profiling, re-tasking and therapeutic switching. Drugs may act through multiple molecular targets. Although perhaps designed for specificity, modulate several targets. This “Poly-pharmacology” may also be essential for efficacy. This “off-targets” may also lead to side-effect. Repositioning vs traditional drug discovery reduces time, reduces risk, and reduces cost.  Bleeding disorder observation of aspirin (a wonder drug) over the years (1891) was made repeatedly leading to the suggestion by Craven (1953) that aspirin might be used for the prevention of thrombosis. The historically unintentional, serendipitous, or constrained research effort is now being replaced by systematic, high-throughput and rational pursuit of new therapeutic uses for marketed drugs, drugs in development, or as a drug salvaging strategy.