Circulatory and metabolic aspects of beta-adrenoceptor blockade.

beta-Blocking therapy is used extensively is conditions as diverse as hypertension, angina pectoris, arrhythmias, thyrotoxicosis, hypertrophic cardiomyopathy, migraine, glaucoma, and myocardial infarction. Studies show they beneficially influence sinus node and atrioventricular conduction, but excessively high doses may cause sinus arrest or sinoatrial block. Nonselective beta-blockade in asthmatic patients may aggravate bronchoconstriction, whereas increased airways resistance is less likely with beta 1-selective, partial agonist, or alpha-beta-blocking drugs. Hypoglycemia can be prolonged; beta 1-selective or partial agonist drugs may cause less interference with glucose metabolism. beta-Blockade affects free fatty acids, lipids and lipoproteins, thyroid hormones, and parathormone. beta-Blockade may normalize abnormal platelet aggregation. Finally, the choice of the most effective drug depends on the clinician's knowledge of the various pharmacodynamic and pharmacokinetic drug profiles, allied with familiarity of the patient's medical condition.