Drug antagonism

Drug antagonism is the stopping of the action or effect of one substance by a medicine, which prevents a biological response. It is carried out by four major mechanisms: chemical antagonism, pharmacokinetic antagonism, receptor antagonism and physiological antagonism. These mechanisms are widely used to reduce overstimulated physiological actions. Drug antagonists appear in many kinds of medication, including anticholinergics and antihistamines, and the antagonistic effect can be quantified through pharmacodynamics. Some antagonists can even serve as antidotes for toxicities and overdose. This entry records the concept of antagonism as a property that medicines can have in relation to other substances rather than a single drug or a single therapeutic area, and it is a description of the idea, not medical advice.