THE CLASSIFICATION OF CALCIUM-ANTAGONISTS AND THEIR SELECTION IN THE TREATMENT OF HYPERTENSION - A REAPPRAISAL

Calcium antagonists have become one of the most important advances in the treatment of hypertension since their introduction over 20 years a go. The increase in the number of available calcium antagonists (as ne w formulations of preexisting drugs or new chemical entities) over rec ent years has contributed to an ever-changing scenario regarding their appropriate use compared with other antihypertensive agents. As a con sequence of this evolving situation, several authors have proposed a 3 -generation classification of calcium antagonists currently, or soon t o be, marketed in several counties. The classification system Is based among other variables, on chemical structure, tissue selectivity, adm inistration frequency and duration of action. In this article, this cl assification is reviewed and updated on the basis of new information t hat is available. In addition, factors which influence the selection o f calcium antagonists in the treatment of hypertension in specific pat ient populations are discussed. As well as pharmacodynamic and pharmac okinetic considerations, these factors also include previous experienc e with particular drugs in specific patient populations, cost of treat ment and drug interactions. Among the dihydropyridine calcium antagoni sts, the first generation compounds have been clearly superseded and a re not recommended for use in hypertensive patients. Whilst the second generation agents represent an adequate treatment, third generation c alcium antagonists possess distinct advantages. Definitive confirmatio n of the role of calcium antagonists in hypertension lies in several o ngoing large multicentre trials.