In clinical practice, there are many kinds of antagonists that can be used to treat different diseases. To understand the classification of antagonists is the premise of using them. The purpose of this essay is to analyze …show more content…
There are many types of antagonists available on the market. If antagonists can be classified according to their characteristics, they would be more convenient to be applied in clinical practice. There are two main categories for antagonists based on whether they combine with receptors. The first type is receptor antagonists that are capable of binding to receptors to inhibit the possession of agonists but do not have intrinsic activity. Receptor antagonists are divided into competitive antagonists and non-competitive antagonists (Rang et al., 2007). The second type is non-receptor antagonists that have two main approaches to prevent agonists. Chemical antagonists and physiologic antagonists are two kinds of non-receptor antagonists to inactive agonists (Golan et al., 2012). The classification of antagonists can see the table below clearly, …show more content…
A non-competitive antagonist binds different active sites with a receptor from an agonist, forms a covalent bond or high affinity with receptor (Golan et al., 2012). If the binding way of noncompetitive antagonists is to form active sites with receptor, it is usually irreversible. Although non-competitive antagonists and agonists do not compete for the same receptor, non-competitive antagonists prevent agonists from binding to receptors. Another situation is, noncompetitive antagonists compete with agonists for the same receptor, but prevents agonists binding with receptors due to covalent bonds Binding way (Golan et al., 2012). The specific example is Verapamil, which is a calcium channel blocker. Verapamil binds to a specific site on the surface of cytoplasmic end, thereby blocking the influx of Ca+( Andersen et al., 2006). Verapamil is able to treat related diseases in the range of 10-20 micromolar (Fleckenstein, 1988). It is used in the high risk of diseases such as angina, hypertension and