Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Xamoterol, a partial-beta 1 agonist, was administered orally (100 mg, twice daily) to healthy volunteers (n = 8) and to patients with heart failure (n = 8) for one week. The density (Bmax) and affinity (Kd) of lymphocyte beta-receptors were lower in the patients with heart failure than in the healthy volunteers (Bmax = 931 +/- 214 vs 1466 +/- 373 sites/cell, and Kd = 0.60 +/- 0.11 vs 1.07 +/- 0.14 nM). During treatment with xamoterol, Bmax (7169 +/- 3768 and 7749 +/- 3807 sites/cell) and Kd (6.01 +/- 3.84 and 9.06 +/- 4.66 nM) increased strikingly (p less than 0.01) in both groups. For 12 months, xamoterol (100 mg bd) was given in the same manner to 10 patients with dilated cardiomyopathy. The long-term effects after three and 12 months were assessed. Xamoterol reduced the cardiothoracic ratio from 57 +/- 6% to 55 +/- 5% after three months and 54 +/- 5% after 12 months of treatment (both p less than 0.05), and increased exercise tolerance from 5 +/- 2 min to 7 +/- 2 min and to 7 +/- 2 min (p less than 0.01, p less than 0.05). Echocardiographic fractional shortening increased from 13 +/- 6% to 20 +/- 8% (p less than 0.01) and to 20 +/- 10% (p less than 0.05). Pulmonary wedge pressure during exercise at the same work load decreased from 40 +/- 12 mmHg to 25 +/- 9 mmHg (p less than 0.01) in three months; whereas pulmonary wedge pressures during exercise or at rest in 12 months were unchanged. Exercise heart rate decreased from 118 +/- 9 beats/min to 106 +/- 6 beats/min in three months (p less than 0.01), but was unchanged in 12 months. Bmax and Kd of the beta-receptors increased from 1024 +/- 413 sites/cell and 0.67 +/- 0.27 nM to 1976 +/- 497 sites/cell and 1.60 +/- 0.42 nM (both p less than 0.01), respectively, in three months, and 1584 +/- 650 sites/cell (NS) and 1.21 +/- 0.54 nM (p less than 0.05), respectively, in 12 months. It is concluded that xamoterol improves exercise tolerance, hemodynamics and resolves subjective symptoms for certain patients with dilated cardiomyopathy by its actions as a beta-agonist and beta-antagonist during longterm treatment.
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PMID:Xamoterol in patients with dilated cardiomyopathy: an increase in beta-receptors in lymphocytes. 290 9

Xamoterol is a partial beta-1 adrenergic agonist capable of stabilising the beta-1 receptor to 43% of their maximal activity. Xamoterol was administered to 10 patients with moderate ischaemic heart failure at an oral dose of 200 mg twice a day. After 3 months, there was an improvement in left ventricular function: 28% reduction in the end-diastolic pressure (p less than 0.01), 12% reduction in ventricular volume (p less than 0.05) with a marked increase in the inotropic state. The exercise tolerance was also increased (+ 30 watt; p less than 0.05) and several indices suggest an improvement in myocardial metabolism. In conclusion, xamoterol is a positive inotrope which does not present the phenomenon of tachyphylaxis during the prolonged administration.
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PMID:[The value of xamoterol in moderate ischemic cardiac insufficiency]. 614 15

Twenty digitalized elderly patients with chronic atrial fibrillation were randomized into a double-blind cross-over study. None was in overt heart failure and all were taking < 80 mg frusemide daily. They received xamoterol 200 mg b.d. for 2 months with their usual dose of digoxin for 1 month and placebo digoxin for the other month. Twenty-four-hour heart rate analysis was done at baseline and at the end of each treatment period. Compared with baseline digoxin, xamoterol alone significantly increased nocturnal minimum heart rate [85 +/- 17 vs. 62 +/- 9 (mean +/- SD), p < 0.0001] without affecting daytime maximum heart rate (132 +/- 18 vs. 122 +/- 20, p = NS). Compared with baseline digoxin, xamoterol plus digoxin significantly increased nocturnal minimum heart rate (68 +/- 8, p < 0.05) and reduced daytime heart rate (114 +/- 17, p < 0.05). The mean number of pauses > 1.5 s was significantly reduced by xamoterol alone. Walking distance in 6 minutes was 406.1 +/- 27.1 m (mean +/- SE) at baseline and improved significantly on both treatments (450.3 +/- 19.8 on xamoterol; p < 0.02 and 453.7 +/- 19.2 on xamoterol plus digoxin; p < 0.01). No significant change was found in subjective measurements of palpitations, breathlessness and well-being using visual analogue scales. Xamoterol combined with digoxin improves effort tolerance and heart-rate control by reducing diurnal tachycardia and nocturnal bradycardia and pauses.
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PMID:Xamoterol improves the control of chronic atrial fibrillation in elderly patients. 748 90

Early studies of acute beta-blocking drug therapy, such as metoprolol and acebutolol, in patients with idiopathic dilated cardiomyopathy (IDC) and survivors of acute myocardial infarction were interpreted to have detrimental or, at best, neutral effects on cardiac and clinical hemodynamics. Subsequent trials of longer duration with metoprolol versus placebo in patients with IDC demonstrated an "exceptional response" to beta-blocker therapy in some individuals. Hemodynamics and patient demographic characteristics appear not to predict those patients who may or may not benefit. Controlled trials with newer beta-adrenoceptor modulating drugs--such as xamoterol, bucindolol, and carvedilol--have been equivocal in some situations. Xamoterol has been associated with progressive heart failure and increased sudden cardiac deaths, whereas bucindolol improved clinical heart failure symptoms and testing hemodynamic parameters, as did treatment with carvedilol, in patients with ischemic cardiomyopathy. The success of these agents in patients with congestive heart failure may be in their ability to modulate the excessive myocardial stimulation of the beta-adrenergic nervous system while benefitting the dynamics of the peripheral system.
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PMID:Controlled trials with beta blockers in heart failure: metoprolol as the prototype. 809 75

Changes were examined in myocardial catecholamine content and alpha 1- and beta 1-adrenoceptors during the development of cardiomyopathy in Syrian hamsters (Bio 14.6) and age-matched healthy controls. In addition, the effects of bunazosin, atenolol, xamoterol, ketanserin, and verapamil on the catecholamine content and [3H]prazosin, [3H]CGP12177 bindings to alpha 1- and beta 1-adrenergic receptors of myocardium were compared with those of the controls. (1) Lower norepinephrine and dopamine levels were observed in 35-week-old cardiomyopathic hamster hearts than in the controls. There was, however, a tendency for a slight decrease of alpha 1- and beta 1-adrenoceptors in cardiomyopathic hamsters. (2) Administration of bunazosin induced lower dopamine values in 18-week-old cardiomyopathic hamsters. (3) Xamoterol induced a higher Kd value for beta 1-adrenoceptors and lower dopamine content than for those with cardiomyopathy. Ketanserin also induced a higher Bmax value than for cardiomyopathy. Thus, drug treatments clearly change catecholamine content and binding characteristics of the adrenoceptors which play an important role in the development of cardiac hypertrophy and heart failure.
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PMID:Cardiomyopathic hamster hearts: long-term effects of drugs on catecholamine contents and binding characteristics of alpha 1- and beta 1-adrenergic receptors. 810 23


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