Some drugs produce effects without altering cellular function and without binding to a receptor. For example, most antacids decrease gastric acidity through simple chemical reactions; antacids are bases that chemically interact with acids to produce neutral salts. The primary action of cholestyramine, a bile acid sequestrant, is to bind bile acids in the gastrointestinal tract.
(See also Overview of Pharmacodynamics Overview of Pharmacodynamics Pharmacodynamics (sometimes described as what a drug does to the body) is the study of the biochemical, physiologic, and molecular effects of drugs on the body and involves receptor binding... read more .)