Classical pharmacology

In the field of drug discovery, classical pharmacology,[1] also known as forward pharmacology,[2][3][4] or phenotypic drug discovery (PDD),[5] relies on phenotypic screening (screening in intact cells or whole organisms) of chemical libraries of synthetic small molecules, natural products or extracts to identify substances that have a desirable therapeutic effect.

Using the techniques of medicinal chemistry, the potency, selectivity, and other properties of these screening hits are optimized to produce candidate drugs.

This approach is known as "reverse pharmacology"[1] or "target based drug discovery" (TDD).

[5] However, recent statistical analysis reveals that a disproportionate number of first-in-class drugs with novel mechanisms of action come from phenotypic screening,[6] which has led to a resurgence of interest in this method.

[7] Pharmacognosy, the investigation of botanics used in indigenous medical traditions is essentially classical pharmacology.