ABSTRACT
Drugs which are useful for medicinal purposes perturb biological systems in a variety of predictable ways. For example, compounds such as antacids are effective due to the ability of their basic chemical properties to neutralize endogenous gastrointestinal acidic products. However, most drugs are effective due to their interactions with specific endogenous proteins, cell membrane components, or genetic material enclosed in the cell nucleus. Psychoactive drugs, in particular, produce their effects due to such interactions with brain neurons.
