Biochemistry Questions / Explain the concept of drug screening and how it is utilized in the development of medications like aspirin and heroin. What are the advantages and limitations of this approach?

Drug screening involves analysing many thousands, or even millions, of molecules to find something that may interact with the desired receptor. Using this process can find a starting molecule that can then be modified and designed to improve its desired biological effect.

This process was used to develop aspirin and heroin, finding very effective molecules. By modifying the starting molecule, salicylic acid in the case of aspirin, by synthetic chemistry, it is possible to produce libraries of derivatives that can then be screened for efficacy. This allows a trial-and-error approach to be used, obtaining the most effective compound. Using a screening approach ensures many candidate molecules are analysed, allowing structures that may have been overlooked to be studied. This could find an unexpected structure that is effective.

Screening involves a lot of trial and error, which can be expensive and time consuming. De novo design of a drug molecule is fast, and with modern computing, cheap.