Beta-Adrenergic Blocking Drugs in the Treatment of Hypertension

Abstract

The reduction in blood pressure seen with the use of beta-blocking drugs was an unexpected finding. Initially there was resistance to their use as the reduction of cardiac output and increase in peripheral resistance from beta-blockade was considered an undesirable pharmacological action for a drug in the treatment of hypertension. However, beta-blockers have now become established in the treatment of hypertension and have been recommended as a first line choice in various guidelines, although their exact mode of action remains a matter for debate. In broad terms beta-blocking drugs are at least of similar efficacy to the other major classes of antihypertensive drugs. They may be usefully combined with other anti-hypertensives, as is often required. There is some evidence that the beta-1 selective agents are more efficacious than the non-selective beta-blockers. Notwithstanding some observations to the contrary beta-blockers are often effective antihypertensive agents in the elderly and in black patients; the combination of being elderly and black, however, appears to result in a reduced fall in blood pressure. If they are given early in pregnancy they lead to a low birth weight. Co-existant disease may influence the choice of a beta-blocker to treat hypertension. Beta-blockers are valuable agents in ischaemic heart disease, notably the control of chronic angina pectoris and to improve prognosis post-myocardial infarction. While initial dose titration has to be extremely careful, heart failure is now a strong indication for the use of a beta-blocker, as prognosis is much improved. Diabetes should no longer be regarded as a contra-indication to the use of a beta-1 selective agent. Recent work confirms that beta-blockers should be given to patients undergoing surgery who have a high cardiac risk. Outcome studies suggest overall that in younger patients beta-blockers reduce the incidence of strokes and myocardial infarction. There is no convincing evidence of a difference between the ACE inhibitor captopril and the combination of diuretic and a beta-blocker. In high risk patients, i.e. those with diabetes, no difference was seen between captopril and atenolol. Diuretics may result in better outcome measurements in the elderly compared to beta-blockade but in combination, "conventional treatment" is as effective in terms of total mortality, strokes and myocardial infarction as ACE inhibitors or calcium antagonists. Co-existant asthma remains an important contraindication to beta-blockade, but not chronic obstructive airways disease where a beta-blocker should be used with caution if it is indicated, e.g. post-infarction. Quality of life measurements, at least with beta-1 selective agents compare favourably with other anti-hypertensive drugs. Beta-blockers, without partial agonist activity, should not be stopped abruptly, particularly in patients with, or at high risk of, co-existant ischaemic disease because of the danger of post-beta-blockade cardiac sympathetic hypersensitivity; alternatively bed rest should be ins...

The latest generation of beta-blockers: New pharmacologic properties

“…Nebivolol has additional properties that cannot be ascribed to β 1 -blocking activity alone, and although similar in its antihypertensive effects, nebivolol differs from other β-blockers in its hemodynamic profile. Thus, although vasodilating β-blockers do not differ from conventional, nonvasodilating β-blockers in their effects on peripheral artery blood pressure [69], these agents may have differential effects on arterial stiffness and central aortic pressure.…”

Simple and rapid HPLC method for simultaneous determination of atenolol and chlorthalidone in spiked human plasma

“…Like other antihypertensive drugs, atenolol lowers the systolic and diastolic blood pressure by 15-20% in a single drug treatment and reduces cardiovascular mortality. It is also used alone or in combination with other antihypertensive agents for the treatment of myocardial infraction, arrhythmias, angina and disorders arising from decreased circulation and vascular constriction, including migraine (Prichard et al, 2001;Wadworth et al, 1991). Atenolol is rapidly but incompletely absorbed after oral administration.…”

Hydrophilic interaction liquid chromatographic tandem mass spectrometric determination of atenolol in human plasma

“…Like other antihypertensive drugs, atenolol lowers the systolic and diastolic blood pressure by 15-20% in a single drug treatment and reduces cardiovascular mortality. It is also used alone or in combination with other antihypertensive agents for the treatment of myocardial infraction (heart attack), arrhythmias (rhythm disorders), angina (chest pains) and disorders arising from decreased circulation and vascular constriction, including migraine (Cruickshank and McAinsh, 1991;Prichard et al, 2001;Wadworth et al, 1991). Many pharmacokinetic investigations have been carried out for atenolol during the past decades.…”