Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1323099 (sympathomimetic)
 2,957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Almost all beta-adrenergic blockers, regardless of their pharmacologic characteristics, appear to have blood pressure-lowering activity in hypertensive patients. Comparisons between nonselective beta-blocking agents, such as propranolol and nadolol, with beta 1-selective drugs, such as metoprolol, atenolol and acebutolol, have demonstrated close similarities in their antihypertensive effects in patients. Similarly, beta blockers with and without intrinsic sympathomimetic activity (ISA) have comparable antihypertensive effects. However, beta-selective agents may offer some advantages over conventional beta blockers in hypertensive patients with concurrent conditions such as chronic obstructive airways disease, peripheral vascular disease, diabetes and hyperlipidemia. Beta 1-selective drugs are also preferred in diabetic patients receiving hypoglycemic agents because they do not interfere with glycogenolysis. Agents lacking ISA, such as propranolol, acutely increase peripheral resistance. beta blockers with ISA usually lower resistance. ISA may also minimize the bradycardia frequently found in elderly patients. Agents with ISA may protect against the decrease in high density lipoprotein cholesterol and the modest increase in triglycerides noted with some beta blockers that do not have ISA. Thus, in a large number of clinical situations in which hypertension is found, the properties of beta 1 selectivity and ISA allow beta blockers to be used with greater safety. Therefore, agents possessing both of these properties may be particularly valuable.
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PMID:Clinical significance of beta 1-selectivity and intrinsic sympathomimetic activity in a beta-adrenergic blocking drug. 288 76

Diuretics and beta blockers are the mainstay in treating mild and moderate systemic hypertension, but there is controversy as to which should be used first. Recent evidence of an increase in sudden death and a greater number of intolerable side effects in the diuretic-treated groups in the Multiple Risk Factor Intervention Trial in the U.S. and the Medical Research Council Trial in Great Britain has prompted some to suggest beta blockers as first-line therapy. However, beta blockers also have side effects, such as decreased ventricular function in patients with mild heart failure, increased airways resistance in those with chronic obstructive lung disease, increased plasma lipids, in particular low density lipoprotein cholesterol, and increased problems in patients with peripheral vascular disease and those with diabetes requiring insulin treatment. Many new beta-blocking drugs with different pharmacokinetic and pharmacodynamic properties allow the physician to choose the best one for each patient. beta-blocking drugs with long durations of action, high levels of bioavailability, beta 1 selectivity and intrinsic sympathomimetic activity appear most suitable for therapy. Cardioselectivity is suggested for patients with obstructive lung disease and peripheral vascular disease, and diabetic patients who take insulin. Long durations of action permit infrequent administration and recently agents with intrinsic sympathomimetic activity have been shown to have less effects on plasma lipid levels. Acebutolol also reduces ventricular arrhythmias, and may therefore be used to reduce sudden death in patients with coronary artery disease. The pharmacokinetic and pharmacodynamic properties of beta-blocking drugs can indicate the most appropriate choice for hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pharmacokinetic and pharmacodynamic properties of beta-blocking drugs influencing choice in treatment of systemic hypertension. 288 49

Clinically significant differences between various beta-adrenoceptor blocking drugs exist. Patients with ischaemic heart disease and exertional angina pectoris benefit from all types of beta-blockers. Drugs with intrinsic sympathomimetic action (ISA) given intravenously may be safer in some patients with acute myocardial infarction than those drugs without ISA. In cardiac patients at rest they may have a vasodilator action and cause less myocardial depression than beta-blockers without ISA. When, however, the cardiac sympathetic tone is high pindolol and other beta-blockers with ISA act as any other beta-blockers, producing haemodynamic impairment. Studies have shown that beta-blockers with ISA confer less benefit in secondary prevention after myocardial infarction and they are not suitable for the treatment of obstructive cardiomyopathy. Non-selective beta-blockers may be advantageous in hypokalaemic arrhythmias. Beta 1-blockers may be preferred for patients with bronchoconstriction, diabetes, peripheral vascular disease and, theoretically to some extent in theory also in patients with hypertension. The extent and nature of side effects may also influence the selection of the most suitable beta-blocker in cardiovascular therapy.
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PMID:Differences in betablocking drugs in cardiovascular therapy. 290 77

The introduction of beta-adrenoceptor blocking drugs initiated a breakthrough in the treatment of various cardiovascular disorders within the last 20 years. The major cardiac indications for beta-blockers are coronary heart disease, hypertension and arrhythmias. No one beta-adrenoceptor blocking drug has been shown to be more efficacious than another, and efficacy can be related to the stereo-selective blockade of adrenergic beta-receptors. The major side effects and the contraindications are mainly due to beta-adrenoceptor blockade in combination with the organ-specific distribution of beta 1- and beta 2-adrenoceptors. In addition to their specific antagonism beta-receptor blocking drugs can differ in beta 1-adrenoceptor selectivity, intrinsic sympathomimetic activity (ISA) as well as in nonspecific effects. However, these ancillary properties do not seem to be of importance for the therapeutic effect of these drugs. A relative beta 1-selectivity is probably able to reduce the incidence of side effects e.g. in asthmatics, in diabetic patients and in patients with peripheral vascular disease, however, beta-adrenoceptor antagonists should be used with caution in these patients, At the present time, there is no convincing evidence that beta-adrenoceptor antagonists with partial agonist activity are superior in patients with congestive heart failure or in asthmatics. Except at high dosages the nonspecific local anaesthetic or cardiodepressant effects of lipophilic beta-adrenoceptor antagonists (propranolol-oxprenolol-group) also do not seem to be of importance in the therapy of cardiovascular diseases. On the other hand, lipophilicity of a lipophilic beta-adrenoceptor antagonists of the propranolol-oxprenolol-group exhibit serum half-lives in the range of two to six hours, whereas half-lives of six to 24 hours are found with the hydrophilic compounds sotalol, practolol, nadolol and atenolol, respectively, while with regard to lipophilicity and serum half-lives timolol, metoprolol, pindolol and acebutolol fall midway between these extremes. It was well established that the duration of action of the beta-adrenoceptor antagonists is about two or three times longer than would be expected from the pharmacokinetic data. This can be explained by the fact that the pharmacodynamic effect obeys zero order kinetics whereas the decline in serum concentration follows first order kinetics. The pharmacokinetic and pharmacodynamic data of the beta-adrenoceptor blocking drugs are of great value in the therapy inasmuch as the dosage interval must be modified accordingly: whereas the lipophilic compounds have to be taken two to four times per day, one dosage per day seems sufficient with the hydrophilic compounds.
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PMID:[Pharmacological basis for the therapy of cardiovascular disease with beta-adrenoceptor blocking drugs (author's transl)]. 612 92

Timolol, a nonselective beta-adrenoreceptor blocking agent without intrinsic sympathomimetic or membrane stabilizing activity, has been shown effective in the treatment of angina and hypertension. It is particularly useful in patients with stable angina pectoris and patients with mild to moderate hypertension. In both of these conditions, timolol appears to be comparable to propranolol. A recent study has suggested that timolol reduces mortality and reinfarction rate in patients who have recently had a myocardial infarction. When given topically timolol reduces intraocular pressure in patients with open-angle glaucoma; the drug may be used as the primary agent or as an adjunct to standard therapy. Careful selection of patients will reduce the frequency of adverse effects due to beta-receptor inhibition. Thus, timolol should not be used in patients who are predisposed to asthmatic bronchitis or cardiac failure, and it should be used with caution in patients with peripheral vascular disease or diabetes mellitus.
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PMID:Pharmacokinetics, mechanisms of action, indications, and adverse effects of timolol maleate, a nonselective beta-adrenoreceptor blocking agent. 676 88

Traditional contraindications to beta-blockers are peripheral vascular diseases, diabetes mellitus, chronic obstructive pulmonary disease (COPD) and asthma. Recent data seem to show that rigorous application of these rules are not completely justified and indicate that many patients would be inappropriately excluded from the beneficial effects of this therapy. Appraisal of clear guidelines for a safe use of beta-blockers is thus mandatory for the clinician. A brief review of the effects of beta-adrenergic receptor blockade is offered. The therapy is aimed at blocking beta 1-receptors. On the other hand, the block of beta 2-receptors causes the well known side effects, i.e. vasoconstriction, delayed response to hypoglycemia in diabetic patients, bronchoconstriction. From the first compound, propranolol, with uniform action on beta 1 and beta 2-receptors, further generation of beta-blockers were subsequently developed: beta 1-selective, with intrinsic sympathomimetic activity, and with associated vasodilating "ancillary" property. Some favorable reduction in collateral effects has thus been obtained with new compounds, without reaching complete safety. Examination of exclusion criteria applied in clinical trials offers no useful indications because of their imprecise definition. Examination of the literature and a more accurate understanding of the diseases, traditionally considered contraindications, may help setting up a uniform and clear path: peripheral vascular disease: beta-blockers should be avoided only in those patients with vasospastic disorders, rest pain with severe peripheral vascular disease or nonhealing lesions. In patients with mild to moderate disease, beta-blockers can be prescribed, but careful surveillance for any changes in symptoms related to intermittent claudicatio should be achieved; diabetes mellitus: previous apprehension for the lessening reaction to hypoglycemia in patients treated with insulin has been retracted. Beta-blockers are not contraindicated in these patients. Some caution should be addressed when signs of autonomic disease are present or in patients with difficult glycemic control. Patients on oral long-acting antidiabetic drugs should not be neglected. The risk of prolonged and paucisymptomatic hypoglycemia while taking beta-blocker agents is somewhat more relevant than in patients treated regularly with insulin; COPD and asthma: confusion may arise if rigorous definition of these diseases and their severity is not applied following the guidelines of the American Thoracic Society. Because bronchial hyperreactivity seems the crucial factor in determining collateral effects to beta-blocker agents, agreement can be reached on the following statements. Beta-blockers are contraindicated a) when history of asthma is present, b) when COPD is moderate to severe, i.e. with FEV1 reduction < 50% of the predicted value, c) in patients on chronic bronchodilator treatment, d) in chronic airflow limitation with evidence of > or = 20% reversibility in airway obstruction in response to inhaled salbutamol. When FEV1 is > 50% of the predicted value, beta-blockers can be given, providing adequate control of stability of ventilatory conditions.
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PMID:[True and presumed contraindications of beta blockers. Peripheral vascular disease, diabetes mellitus, chronic bronchopneumopathy]. 1099 10