Pharmacology is a part of biology. . . . Of all the vast number of pharmacologic reactions, those which the physician attempts to use for curative purposes are of the greatest interest and most deserved of study. A medicine or preparation with no inherent pertinent pharmacologic activity which is effective only by virtue of the factor of suggestion attendant upon its administration. A drug preparation incorporated into an experiment with the intention that it have effects on the experimental system qualitatively similar to those expected of the independent variable. A measure of drug activity established by determining the dose of a drug required to produce a standard effect.
Potency varies inversely with the magnitude of the dose required to produce a given effect.
For example. although physostigmine has no acetylcholine-like activity of its own, it potentiates the actions of acetylcholine by inhibiting the enzymes responsible for the destruction of acetylcholine. The change may be a result of biotransformation, or may occur spontaneously, in the presence of, e.g., water, an appropriate pH, etc. The square of the reciprocal of the index of precision is the measure of the amount of information that can be delivered by the system. Specifically, precision is computed in several steps. See Accuracy .