Classification of antiarrhythmic agents and the two laws of pharmacology
Luc M. Hondeghem · Cardiovascular Research · 2000
In a standard textbook of pharmacology [1] there are 50 (three-column, 69-line) pages in the index (50×3×69=10 350). In order to render this vast information somewhat manageable the chemicals are grouped in about 50 chapters, one of which is “Agents used in cardiac arrhythmias” [2]. Antiarrhythmic agents are in turn subdivided in four classes plus a group of miscellaneous agents (containing those that do not fit in any of the four standard classes). At times it is desirable to subdivide these classes into subclasses (main topic of this paper). Although such classification renders the pharmacological information more manageable, it is frequently difficult or impossible to fit a chemical in a class. For example, while beta blockers certainly belong as a chapter in the section on autonomic drugs, they also form an important class in the antiarrhythmic agents (see below). In addition, they also need to be described in the sections on angina, congestive heart failure and hypertension (among others). This problem follows directly from the first law of pharmacology: no drug has a single effect.