Required beta blocker profile in the elderly

In the truly elderly, a complex balance between compensatory processes and impaired organ function allows reasonably normal physical function. It is argued that beta blockade should have certain desirable qualities to minimize any impairment of organ function, thereby upsetting the quality of life. Thus a simple pharmacokinetic pattern without hepatic metabolism is less likely to cause unexpected variation in blood levels of the beta blocking agents and to have fewer risks of interactions with other drugs including nicotine. Renal-excreted beta blockers--such as atenolol, nadolol, and celiprolol--do, however, need downward dose adjustment when the glomerular filtration rates fall. The elderly are frequently categorized as having a low renin profile, which in the view of some workers may make a vasodilatory beta blocker more desirable. Hemodynamic advantages of such agents include the prime site of attack in hypertension on the increased peripheral vascular resistance, increasingly fundamental with a prolonged duration of hypertension and therefore with the aging process. Furthermore, a normal heart rate with a sustained cardiac output may avoid symptomatic bradycardia. In the elderly, respiratory function may be impaired so that loss of elastic recoil causes elderly emphysema. A highly cardioselective beta blocker should be an advantage. Finally, minimal interference with glucose and lipid metabolism should also be desirable goals.

A pressor effect of noncardioselective beta-blockers in mildly hypertensive patients during acute hospitalization

Pressor effects of noncardioselective beta-blockers have been demonstrated in situations of increased sympathetic activity; however, data are limited and the clinical significance of this finding is in doubt. The present study was performed to supply data about the effect of noncardioselective beta-blockers on the stress of acute hospitalization. Of 2,989 patients acutely admitted to a 50-bed unit of general internal medicine in a 647-bed teaching hospital, 234 had used beta-blockers without intrinsic sympathicomimetic activity (ISA) for at least six weeks because of mild hypertension; 199 were evaluable, 56 using nonselective, 143 using selective beta-blockers. The authors found a marked pressor effect of noncardioselective beta-blockers as compared with selective (mean arterial pressure 125 versus 102 mm Hg, p less than 0.001). In the patients who could continue their outpatient medication this effect could be attributed to an overall increase of total peripheral resistance and disappeared within five days of admission. In the patients admitted because of unstable angina pectoris (nonselective n = 15, selective n = 48) myocardial oxygen demand as estimated by the double product (systolic blood pressure heart rate) was significantly higher in the nonselective group (12.926 versus 9.581 mmHg.beats/min, p less than 0.01). The present study supports the need for more controlled data to determine the ultimate place of noncardioselective beta-blockers in situations of increased sympathetic activity.

Pressor responses from noncardioselective beta-blockers

This study reviews more than fifty papers dealing with pressor responses from noncardioselective beta-blockers. It is concluded that the responses are usually mild. They occur mainly in situations of increased sympathetic activity. Therefore some patients seem to be at risk, eg, patients with unstable diabetes type 1, sportsmen performing isometric exercise, and heavy smokers. In orthostatic hypotension, noncardioselective beta-blockers may be beneficial. Cardiac output tends, however, to decrease, and patients with orthostatic hypotension will probably not benefit from this effect.

Qualities of an ideal beta-adrenoceptor antagonist and comparison of existing agents with a new cardioselective hydrophilic vasodilator beta-adrenoceptor antagonist, celiprolol

Beta-adrenoceptor blockade is established therapy for cardiovascular conditions including hypertension and angina pectoris. The important qualities of a beta-adrenoceptor antagonist relate to cardioselectivity, hydrophilicity, peripheral vasodilation, ideal pharmacokinetics and maintenance of the quality of life. Celiprolol, with its known cardioselectivity, hydrophilicity and peripheral vasodilator capacity, measures well by several of these criteria; more data on pharmacokinetics are required. Further testing is indicated, particularly in relation to effects on epinephrine-induced hypokalemia, blood lipid profiles, clinical vasodilatory properties and effects on the quality of life, especially in geriatric patients.

Adverse reactions and interactions with beta-adrenoceptor blocking drugs

beta-Blocking drugs are widely used throughout the world and serious adverse reactions are relatively uncommon. Most of those which do occur are pharmacologically predictable and may be avoided by ensuring that patients who are to be given beta-blockers do not have a predisposition to the development of bronchospasm, cardiac failure or peripheral ischaemia. In some situations, the use of a beta 1-selective blocking drug may reduce the risk of a severe adverse reaction, but there is little evidence that other ancillary properties such as partial agonist activity are of relevance in this context. Long term experience with many of the beta-blockers in current use suggests that unpredictable major adverse reactions such as the practolol oculomucocutaneous syndrome are unlikely to be repeated, although some of these drugs may be associated with immunological disturbances and some have been implicated in the development of retroperitoneal fibrosis. beta-Blocking drugs appear to be associated with a number of subjective side effects including muscle fatigue, peripheral coldness and some neurological symptoms. These side effects are highly subjective and are therefore difficult to quantify and it is not known whether they are of major importance in terms of their effect upon patients' overall well-being. It cannot be assumed that simply because such side effects can be elicited that they do, in fact, matter. However, because beta-blockers are often prescribed for patients who have no symptoms and for whom the benefits of therapy are generally small, such side effects would be of considerable importance if they had an overall effect upon quality of life. There are theoretical reasons to suppose that the incidence and severity of such side effects may be related to the ancillary properties of the individual drugs, but there is little evidence that parameters such as beta 1-selectivity, or partial agonist activity are clinically important determinants of the severity of these side effects. Lipophilicity, however, may be associated with an increased incidence of neurological symptoms. beta-Blocking drugs may cause a variety of metabolic disturbances including an increase in serum VLDL-cholesterol concentrations. However, long term studies have not shown that such disturbances are associated with an increased risk of cardiovascular disease, indicating that such metabolic changes may not be of major importance in practice. beta-Blocking drugs may be involved in a number of interactions with other drugs, but few of these have been shown to be of clinical significance.(ABSTRACT TRUNCATED AT 400 WORDS)

Beta-blockers and glucose control

Literature on the effects of beta-blockers on blood glucose is reviewed. Data are presented regarding the adrenergic influences on glucose regulation and the effects of beta-blockade during hypo- and hyperglycemia in normal and diabetic individuals. beta-adrenergic stimulation enhances insulin and glucagon secretion, as well as glycogenolysis, gluconeogenesis, and lipolysis. alpha-adrenergic stimulation inhibits insulin secretion and may inhibit glucagon secretion and enhance liver glycogenolysis. In nondiabetics, beta-blockers represent minimal risk of affecting glucose control. In insulin-dependent diabetics, beta-blockers can prolong, enhance, or alter the symptoms of hypoglycemia, while hyperglycemia appears to be the major risk in noninsulin-dependent diabetics. beta-blockers can potentially increase blood glucose concentrations and antagonize the action of oral hypoglycemic drugs.