Comparative Efficacy of Three Long-Acting β-Receptor-Blocking Agents against Conventional Propranolol: β-Receptor Blockade in the 24Th Hour after a Single Dose

1981 ◽  
Vol 60 (3) ◽  
pp. 7P-7P
Author(s):  
G. R. Jones ◽  
M. A. Mir
Keyword(s):  
Single Dose ◽  
Receptor Blockade ◽  
Comparative Efficacy ◽  
Receptor Blocking ◽  
Blocking Agents ◽  
Β Receptor ◽  
Long Acting

Quantitative Effects of Timolol and Hydrochlorothiazide on Blood Pressure, Heart Rate and Plasma Renin Activity: Results of a Double-Blind Factorial Trial in Patients with Essential Hypertension

1976 ◽  
Vol 51 (s3) ◽  
pp. 517s-519s
Author(s):  
J. P. Chalmers ◽  
J. S. Horvath ◽  
P. I. Korner ◽  
D. J. Tiller ◽  
A. J. Bune ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Renin Activity ◽  
Receptor Blockade ◽  
Double Blind ◽  
Receptor Blocking ◽  
Placebo Phase ◽  
Factorial Trial ◽  
Β Receptor

1. The anti-hypertensive actions of timolol and hydrochlorothiazide were analysed in a double-blind 2 × 2 factorial trial in twenty patients with essential hypertension. Each patient went through four phases of 8 weeks in randomized order, receiving timolol alone, hydrochlorothiazide alone, timolol plus hydrochlorothiazide, and placebo. 2. Supine mean arterial pressure fell from 119 mmHg in the placebo phase, to 110 mmHg during the thiazide phase, 106 mmHg during the timolol phase, and to 101 mmHg during the combined timolol plus hydrochlorothiazide phase. 3. Factorial analysis revealed that the hypotensive actions of the β-receptor-blocking drug and the diuretic were additive, without any synergism or antagonism. 4. Plasma renin activity measured in ng 3 h—1 ml—1 rose from 502 in the placebo phase to 9·54 in the diuretic phase, but fell to 1·79 in the β-receptor blockade. It was unchanged in the combined therapy phase, despite the greater drop in blood pressure. These results suggest that the fall in plasma renin activity during β-receptor blockade is of little importance in the hypotensive action of β-receptor-blocking drugs.

β-Receptor-Blocking Agents May Reverse or Prevent Diuretic-Induced Increases in Serum Low-Density Lipoprotein Cholesterol

1981 ◽  
Vol 61 (s7) ◽  
pp. 437s-439s ◽  
Author(s):  
A. Meier ◽  
H. Schiffl ◽  
P. Weidmann ◽  
R. Mordasini ◽  
W. Riesen ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Receptor Blocking ◽  
Blocking Agents ◽  
Group I ◽  
Β Blocker ◽  
Β Receptor

1. The effect of treatment with a thiazide-like diuretic alone or combined with a β-adrenoceptor blocker on serum lipoproteins was investigated in 35 patients with essential hypertension. 2. In group I (18 patients), serum low-density lipoprotein cholesterol was increased (P < 0.001) during monotherapy with chlorthalidone (100 mg/day) but not during combined chlorthalidone-β-blocker therapy. 3. This tendency was similar in subgroups studied with an inverse sequence of drug administration. In subgroup IA (11 men), a 22% increase (P < 0.01) in low-density lipoprotein cholesterol after 6 weeks of chlorthalidone was reversed after use of a β-blocker as well as chlorthalidone; in subgroup IB (five men, two post-menopausal women), low-density lipoprotein cholesterol was increased by 41% (P < 0.05) above placebo values 6 weeks after withdrawal of the β-blocker from combination therapy. 4. In group II (18 men), low-density lipoprotein cholesterol was increased by 13% (P < 0.025) after 4 weeks of monotherapy with clopamide (5 mg/day) but restored to control levels 4 weeks after addition of pindolol (10 mg/day). 5. No significant changes occurred during any treatment phase in high-density lipoprotein cholesterol. 6. Certain β-receptor blocking agents may prevent or reverse diuretic-induced increases in serum low-density lipoprotein cholesterol.

scholarly journals AN EXPERIMENTAL STUDY OF THE β-RECEPTOR BLOCKING AGENTS ON THE CARDIAC PERFORMANCE IN DOGS

1970 ◽  
Vol 20 (4) ◽  
pp. 467-472
Author(s):  
N. SINGH ◽  
R.K. SRIVASTAVA ◽  
V.K. KULSHRESTHA ◽  
J.N. SINHA ◽  
R.P. KOHLI ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cardiac Performance ◽  
Receptor Blocking ◽  
Blocking Agents ◽  
Β Receptor

Pharmacokinetics of β-Receptor-Blocking Agents in Relation to Their Anti-Hypertensive Effect

1976 ◽  
Vol 51 (s3) ◽  
pp. 473s-475s
Author(s):  
R. Gugler ◽  
G. Bodem ◽  
H. J. Dengler
Keyword(s):  
Liver Blood Flow ◽  
Systemic Availability ◽  
Receptor Blockade ◽  
Hypertensive Patients ◽  
Receptor Blocking ◽  
First Pass ◽  
High Doses ◽  
Β Receptor ◽  
Plasma Half Life ◽  
Propranolol Therapy

1. β-Receptor-blocking drugs are rapidly and completely absorbed after oral administration. Systemic availability is nevertheless incomplete for propranolol, alprenolol and oxprenolol, owing to ‘first-pass’ extraction by the liver. 2. Plasma half-life is between 2 and 4 h, except for sotalol (10–12 h). Plasma elimination of propranolol is reduced with decreased liver blood flow, observed in congestive heart failure or during chronic propranolol therapy itself. 3. β-Receptor blockade is usually achieved in these concentration ranges: propranolol and alprenolol, 50–100 ng/ml; oxprenolol, 500–1000 ng/ml; pindolol, 10–30 ng/ml; sotalol, 2–6 μg/ml. Higher concentrations are often found with high doses administered to hypertensive patients.

Effects of alpha-adrenergic receptor blockade on coronary circulation in conscious dogs

1982 ◽  
Vol 243 (1) ◽  
pp. H94-H98
Author(s):  
P. Macho ◽  
T. H. Hintze ◽  
S. F. Vatner
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Adrenergic Receptor ◽  
Coronary Circulation ◽  
Conscious Dogs ◽  
Receptor Blockade ◽  
Receptor Blocking ◽  
Blocking Agents ◽  
Alpha Adrenergic Receptor ◽  
Adrenergic Receptor Blockade

The effects of three alpha-adrenergic-receptor blocking agents (phentolamine, prazosin, and trimazosin) were compared on the coronary circulation and left ventricular (LV) function in chronically instrumented conscious dogs. The three alpha-adrenergic-receptor blocking agents were administered in equidepressor doses (mean arterial pressure fell by approximately 20%) and in the presence of beta-adrenergic-receptor blockade and constant heart rate. LV systolic pressure, LV end-diastolic pressure, and LV end-diastolic diameter also fell similarly with the three drugs. Phentolamine decreased the time rate of change of LV pressure (LV dP/dt) by 21 +/- 3%, whereas trimazosin and prazosin decreased LV dP/dt only by 14 +/- 2 and 11 +/- 2%, respectively. LV velocity was not changed with trimazosin and prazosin but decreased with phentolamine by 12 +/- 4%. The three drugs exerted differential effects on the coronary circulation. Only trimazosin increased coronary blood flow (18 +/- 5%). Trimazosin decreased late diastolic coronary resistance (LDCR) by 35 +/- 2%, which was significantly more than reductions in LDCR induced by prazosin (22 +/- 2%) and by phentolamine (11 +/- 3%). A test dose of phenylephrine (5.0 micrograms/kg) increased mean arterial pressure by 53 +/- 3.5 mmHg. After trimazosin, prazosin, and phentolamine, the same dose of phenylephrine increased mean arterial pressure by 24 +/- 2.1, 14 +/- 1.6, and 1.9 +/- 0.6 mmHg, respectively. The response after phentolamine was significantly less than with trimazosin (P less than 0.01) and prazosin (P less than 0.02). Thus the capacity of these three alpha-adrenergic-receptor blocking drugs to dilate coronary vessels is inversely proportional to their capability to block exogenous alpha-adrenergic-receptor agonists.

A comparison of the cardiovascular actions of four adrenergic β-receptor blocking agents in resting, conscious dogs

1971 ◽  
Vol 82 (3) ◽  
pp. 338-351 ◽  
Author(s):  
Mario Bergamaschi ◽  
Robin G. Shanks ◽  
Anna M. Caravaggi ◽  
Virginio Mandelli
Keyword(s):  
Conscious Dogs ◽  
Receptor Blocking ◽  
Blocking Agents ◽  
Cardiovascular Actions ◽  
Β Receptor

Effect of β-Receptor-Blocking Agents on Cardiovascular Structural Changes in Spontaneous and Noradrenaline-Induced Hypertension in Rats

1980 ◽  
Vol 59 (s6) ◽  
pp. 457s-460s ◽  
Author(s):  
Yukio Yamori ◽  
R. C. Tarazi ◽  
Akira Ooshima
Keyword(s):  
Blood Pressure ◽  
Protein Synthesis ◽  
Structural Changes ◽  
Cardiovascular Response ◽  
Left Ventricular ◽  
Spontaneously Hypertensive ◽  
Receptor Blocking ◽  
Blocking Agents ◽  
Collagen Protein ◽  
Β Receptor

1. Continuous intravenous noradrenaline infusion for 1 week into rats by osmotic minipumps significantly increased blood pressure and left ventricular weight. 2. Concomitant α-receptor-blockade infusion significantly lowered blood pressure and the aortic weight without significant reduction in left ventricular weight. 3. Two β-receptor-blocking agents in noradrenaline-infused rats normalized left ventricular weight and significantly reduced the aortic weight, although blood pressure was still higher than control non-infused rats. 4. In 7-week-old spontaneously hypertensive rats, propranolol (perorally for 2 weeks) did not lower blood pressure but reduced significantly cardiovascular protein synthesis ([14C]lysine and [3H]uridine incorporation into non-collagen protein and RNA respectively) in both left ventricle and aorta. This effect was in contrast to hydrallazine, which normalized blood pressure but did not reduce cardiovascular protein synthesis. 5. Results suggest that β-receptors play a modulating role in the structural cardiovascular response to blood pressure.

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