Classical vs reverse pharmacology in drug discovery

The evolution of medical treatments has made remarkable strides thanks to advances in the technology used in drug discovery. In the early days of pharmacology, therapeutic drugs were created from derivatives of medicinal plants. This was the case for aspirin, which was derived from the bark of the willow tree. Some bene®cial drugs have been discovered incidentally during scienti®c research. These desirable accidental discoveries are referred to as drug serendipity. In the 1960s, advances in pharmacology led to an elucidation of the function of cellular receptors, ion channels and enzymes. This information allowed the process of drug discovery to become more scienti®c and rational. It was during this period that many of the useful drugs that are currently still prescribed were discovered, including a-blockers, b-blockers, and calcium antagonists. A genome is the complete set of genes in an organism. Genomics is of increasing interest to world leaders and was one of the topics discussed at the Summit of Industrialized Nations held in Okinawa in June 2000. The study of the human genome is certain to have an increasingly important role in the discovery of new therapeutic drugs, especially in light of the recent description of the entire human genome, which showed that humans possess almost twice as many genes as the fruit ̄y, Drosophila melanogaster. The advent of molecular cloning techniques has enabled many receptor and ion channel molecules to be classi®ed, based on similarities in their amino-acid sequence and protein structure. One of the greatest challenges currently facing pharmaceutical companies is to assimilate the vast amount of information generated by genomic and proteomic research into drug discovery programs.