CHOOSING THE RIGHT BETA-BLOCKER - A GUIDE TO SELECTION

beta-Blockers have been in clinical use for 30 years, and have an acce pted role in (among others) the treatment of high blood pressure, the secondary prevention of myocardial infarction and the treatment of arr hythmias. Their place in the treatment of heart failure is currently u nder investigation. The drugs available in the 1970s and early 1980s w ere subjected to intense investigation. A new generation of beta-block ers, including some such as carvedilol and bucindolol, with vasodilati ng properties, is now appearing. As yet these later agents have not be en the subject of large clinical trials. Clinical practice involves th e treatment of individual patients with defined dosages of particular drugs. It is, therefore, not acceptable to base practice on theories d erived from the clinical pharmacology of a particular drug, on the res ults of small trials or on a meta-analysis of results from a number of trials that were individually inadequate. Clinical practice must foll ow the results of large-scale trials in defined populations. The major trials in hypertension, myocardial infarction, arrhythmias and heart failure provide the best evidence for the use of individual beta-block ers in each of these clinical situations. In patients with high blood pressure, beta-blockers do not seem to have any particular advantage o ver other hypotensive agents. In myocardial infarction, relatively lat e use of a beta-blocker undoubtedly reduces fatality, though the value of early treatment is less clear. beta-Blockers are not powerful anti arrhythmics, but they do appear to prevent sudden death. Their possibl e role in heart failure is perhaps the most interesting current field of beta-blocker research. There are very few comparative studies of be ta-blockers, and it is difficult to make precise recommendations. None of the new generation of beta-blockers has yet been used in a trial t hat is large enough trial for any of them to be accepted for routine u se in preference to older drugs. The use of individual beta-blockers, as with any drug should follow the results of clinical trials. Propran olol and atenolol have been studied most intensely in hypertension. Fo r secondary prevention of myocardial infarction, the evidence is best for timolol. Sotalol is probably the best antiarrhythmic among the bet a-blockers. Whether any individual beta-blocker is best for heart fail ure remains to be seen.