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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The antihypertensive efficacy of bevantolol, a selective beta 1-adrenoreceptor antagonist, was evaluated in 17 patients with essential hypertension, using continuous ambulatory intraarterial blood pressure (BP) monitoring. The study compared a twice-daily regimen (titrated dose of 200 to 600 mg/day) with the same amount given in a single daily dose. Within-patient comparisons of mean hourly systolic and diastolic BPs and heart rate showed a highly significant effect with twice-daily therapy (p less than 0.001) for all of the 24 hours. Similar significant results were obtained with a single morning dose. There was no difference between the pattern or extent of BP reduction with the 2 regimens. The decrease in BP after bevantolol persisted during the physiologic tests (rest, tilt, isometric and dynamic exercise). Four patients developed minor side effects with the single morning dose, and only 1 patient with the twice-daily regimen. These effects included tiredness, fatigue and dizziness. Unlike pure beta-blocking agents, bevantolol controlled the early morning increase in BP, lending support to the belief that it possesses vasodilatory properties in addition to beta blockade. These results suggest that bevantolol may be useful as first-line therapy in a once-daily dosage for the treatment of essential hypertension.
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PMID:Once- and twice-daily bevantolol for systemic hypertension using 24-hour ambulatory intraarterial blood pressure recording. 287 95

Both nonselective beta-blockers and beta 1-selective blockers are effective antihypertensive agents. beta 1-Blockade generally is considered to be responsible for their antihypertensive action, whereas beta 2-blockade is regarded as undesirable. These common assumptions notwithstanding, the mechanism by which beta-blockers lower blood pressure remains unknown. To examine the possibility that beta 2-blockade may contribute to the antihypertensive action of beta-blocker therapy, we studied the cardiovascular effects of compound ICI 118551, a beta 2-selective blocker. First, we showed that 50 mg t.i.d. orally is a beta 2-selective dose. In contrast to propranolol, 80 mg t.i.d., or atenolol, 100 mg once a day, 50 mg of ICI 118551 t.i.d. failed to block beta 1-mediated inotropic stimulation and stimulation of renin by isoproterenol. We then performed a double-blind, placebo-controlled trial in patients with mild essential hypertension to compare this compound with propranolol, 80 mg t.i.d., and showed that ICI 118551 significantly decreased systolic and diastolic blood pressure. This antihypertensive effect was demonstrated by direct as well as by indirect blood pressure measurements. Thus, contrary to prevailing thought, beta 2-blockade has an antihypertensive effect independent of, and distinct from, beta 1-blockade.
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PMID:Is beta 1-antagonism essential for the antihypertensive action of beta-blockers? 288 Aug 4

Indenolol is a new antihypertensive agent, whose beta 1-adrenoceptor antagonist properties combined with beta 2-adrenoceptor agonist properties have been shown by experimental studies in animals. Our previous work reported that in vivo beta-adrenoceptor blocking drugs markedly increase the beta-adrenoceptor (BAR) number, without increasing BAR affinity. The aim of this study was to evaluate BAR density and affinity before and after indenolol therapy in membranes of polymorphonucleates (PMN) of patients with essential hypertension. Polymorphonuclear binding parameters were studied in 12 hypertensives (WHO stages I and II) after 14 days of placebo and after 21 days of indenolol therapy (120 mg once daily orally). Indenolol did not increase BAR number but significantly decreased (P less than 0.01) BAR affinity. On the basis of these data it is concluded that indenolol does not induce the same changes in PMN's BAR as previously observed with oxprenolol, propranolol and labetalol. This phenomenon may account for the absence of rebound effect after withdrawal of indenolol in hypertensives.
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PMID:Effect of indenolol treatment on beta-adrenergic receptors of polymorphonucleates in essential hypertension. 288 69

The effects of long-term (6 months) antihypertensive treatment with three different types of beta-blockers (propranolol, nonselective without ISA; pindolol, nonselective with ISA; metoprolol, beta 1-selective without ISA) on submaximal exercise capacity and metabolic variables during submaximal endurance exercise were studied in seven subjects with essential hypertension. Exercise tests were performed on a bicycle ergometer at 70% of estimated VO2 max. Similar reductions of resting and exercise blood pressure and exercise heart rate were obtained with the three beta-blockers. Exercise time was significantly reduced by all three beta-blockers during chronic antihypertensive therapy. The reduction tended to be more pronounced after 5-6 months of treatment than after 1 week (P = 0.06). During exercise, the plasma glycerol and nonesterified fatty acid concentrations were reduced. Plasma glucose concentration was reduced at the end of the exercise test during propranolol treatment only. Plasma lactate concentrations tended to be increased, but the difference was significant during pindolol treatment only. Oxygen uptake tended to decrease and respiratory exchange ratio to increase. Plasma potassium concentrations during exercise were significantly increased with all three beta-blockers. The effects on the metabolic variables during exercise were similar after 1 week and during long-term (20/24 weeks) beta-blocker treatment. The study shows that submaximal endurance exercise capacity is impaired in patients with essential hypertension on beta-blocker therapy and that the impairment is maintained during long-term antihypertensive beta-blocker treatment.
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PMID:Long-term antihypertensive therapy with beta-blockers: submaximal exercise capacity and metabolic effects during exercise. 289 May 91

Bevantolol is a novel beta 1-selective beta-adrenoceptor antagonist. The Study Group evaluated its therapeutic utility (100-300 mg bid) compared with propranolol (80-240 mg bid) in 266 patients with mild to moderate essential hypertension (WHO Grades I and II, sitting diastolic blood pressure (DBP) greater than or equal to 95 mmHg). There was no difference in their antihypertensive efficacy over six months, 77% being controlled (DBP less than or equal to 90 mmHg) on bevantolol and 81% on propranolol. Hydrochlorothiazide 25-50 mg bid added later improved BP control in those incompletely controlled on bevantolol monotherapy. Both beta-adrenoceptor antagonists also reduced intraocular pressure. Bevantolol caused significantly fewer adverse effects than propranolol with many fewer withdrawals during long-term therapy. This unique clinical pharmacologic profile of bevantolol enhances its therapeutic usefulness and may relate to alpha-adrenoceptor antagonist activity, as well as to its beta 1-selectivity.
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PMID:Bevantolol vs propranolol: a double-blind controlled trial in essential hypertension. 289 12

This survey covers the classification and subdivisions of alpha- and beta-adrenoceptors, including alpha 1 and alpha 2, beta 1 and beta 2, and pre-and postsynaptic receptor subtypes, together with the distribution and functional relevance of the various adrenoceptor subtypes. The emphasis will be on their relevance in circulatory regulatory processes, especially those of the blood vessels. The alpha- and beta-adrenoceptor antagonists that interact with various receptor subtypes are briefly discussed. The control of alpha 2-adrenoceptors concerned with blood pressure regulation is an important target for centrally acting antihypertensive drugs (such as clonidine or alpha-methyldopa). Changes in adrenoceptor density, particularly the down-regulation of beta 1- adrenoceptors (but not beta 2), are found in congestive heart failure. However, the experimental findings about alpha-and beta-adrenoceptors in essential hypertension remain controversial. Finally, the influence of alpha- and beta-adrenoceptor antagonists on plasma lipids and carbohydrate metabolism is briefly reviewed. The changes found may be only partly explained on the basis of alpha- or beta-receptor blockade.
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PMID:The role of adrenoceptors in circulatory and metabolic regulation. 290 48

Bisoprolol is a beta 1-adrenoceptor antagonist with no partial agonist (intrinsic sympathomimetic) activity or membrane stabilising (local anaesthetic) activity. The oral bioavailability of bisoprolol is high (90%) and the drug has a long elimination half-life which allows once-daily administration; in addition, it is hepatically and renally cleared in equal proportions. In non-comparative studies, and comparative trials, bisoprolol proved effective, and as efficacious as atenolol, low doses of metoprolol, diuretics and nifedipine SR in hypertension, and atenolol and verapamil in stable angina pectoris. Bisoprolol has been well tolerated in most patients. Thus, bisoprolol is an effective alternative to other beta-adrenoceptor antagonists in patients with mild to moderate essential hypertension or stable angina pectoris. Furthermore, its unique pharmacokinetic properties may offer advantages in selected patients. However, the results of further comparative studies with established agents in the treatment of hypertension and angina pectoris are still awaited so that a final assessment of the relative place in therapy of bisoprolol in these disease states may be made.
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PMID:Bisoprolol. A preliminary review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in hypertension and angina pectoris. 290 20

The aim of this study was to evaluate the possible time-related effects of long-term monotherapy with different beta-blockers on plasma lipids in patients with essential hypertension. We studied 69 mild-moderate hypertensives, all males, aged 35-56 years belonging to the same working community. After 1-month placebo period, patients were assigned to receive propranolol 160 mg/day or atenolol 100 mg/day or bisoprolol 10 mg/day or mepindolol 10 mg/day. They were followed-up for 2 years. Blood pressure (BP), heart rate and blood samples for evaluation of total cholesterol (TC), LDL-cholesterol (LDL-C), triglycerides (TG) and HDL-cholesterol (HDL-C) were taken before and after placebo period and every 6 months from the beginning of the active treatment. All beta-blockers caused similar reduction in BP values which persisted throughout the study. None of the beta-blockers significantly affected TC and LDL-C. Propranolol caused the most pronounced changes in TG (+35-43%) and in HDL-C (-36-44%). Atenolol had the same qualitative effects but to a lesser extent (TG: +26-30%; HDL: -15-25%). Bisoprolol has more beta 1-selective than atenolol, and mepindolol, non-selective with ISA, increased TG (+15-28% and +13-23%) but did not significantly affect HDL-C. Consequently, HDL-C and TG changes appeared to be related to the ancillary properties of the different beta-blockers and, in a lesser degree, to the duration of therapy.
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PMID:Effects of different beta-blockers on lipid metabolism in chronic therapy of hypertension. 290 41

To determine whether beta-adrenoceptor blockade lowers blood pressure by potentiating arterial baroreflex sensitivity (BRS), we compared the effect of acute i.v. and chronic oral beta-blockade on the BRS (phenylephrine technique) of 51 subjects with essential hypertension. Subjects were randomly assigned in a double-blind protocol to one of atenolol, metoprolol, pindolol or propranolol. There was an increase in BRS, unrelated to changes in heart rate, after both acute and chronic beta-blockade. This effect was most evident in younger and less hypertensive subjects. Decreases in blood pressure after 5-months' treatment were unrelated to increases in BRS, indicating that the hypotensive action of these drugs is not dependent upon augmented baroreflex control of heart rate. Only propranolol, of the 4 beta-blockers, increased BRS significantly after acute and chronic treatment. The acute effect of propranolol was significantly different from that of i.v. metoprolol (P less than 0.008) but the effect of long-term treatment with propanolol was not significantly different from that of the other 3 beta-blockers. We conclude that the impaired reflex regulation of heart rate can be improved in younger and mild-to-moderate hypertensive patients by beta-adrenoceptor blockade. Further studies, involving larger numbers and perhaps fewer drugs are needed to determine the relative importance of lipophilicity and beta 1- or beta 2-receptor selectivity in mediating the increase in baroreflex sensitivity seen with treatment.
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PMID:Effects of acute and chronic beta-adrenoceptor blockade on baroreflex sensitivity in humans. 290 53

Antihypertensive therapy with celiprolol lowers blood pressure by selectively blocking beta 1 adrenoceptors. It also exhibits vasodilatory and bronchosparing effects and is not cardiodepressive. Because many beta blockers are often suspected of adversely raising serum lipid levels, especially triglycerides, a special investigation of lipids in hypertensive subjects was performed. The preliminary findings in a series of 14 patients (average age 39.7 years) with essential hypertension (World Health Organization stages I to II) who were treated with celiprolol for a period of 6 months are presented. Serum levels of total cholesterol and low-density lipoprotein remained virtually unchanged during treatment. There was, however, a tendency for triglyceride levels to fall with celiprolol treatment, a trend that became significant after 4 weeks. Moreover, high-density lipoproteins tended to increase with treatment and were significantly increased after 2 weeks. In contrast to findings obtained with other beta-blocking agents, no increases in total serum lipids were observed during celiprolol treatment. Blood pressure values of the subjects treated decreased significantly from a mean value (measured in the upright position) of 151/99 to 131/87 mm Hg. Blood pressure values taken in the supine position were also significantly reduced. No significant changes were noted in a variety of laboratory parameters, including blood count, blood coagulation time, blood sugar concentration, liver and kidney tests, electrolyte levels and urinalysis. The significance of these results, which suggest that celiprolol is not associated with adverse changes of lipids and may even positively influence blood chemistry, is discussed.
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PMID:Effects of celiprolol on serum lipids in systemic hypertension. 296 24


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