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.

Compared Incidence of First Myocardial Infarction in Hypertensive Patients under Treatment Containing Propranolol or excluding β-Receptor Blockade

1976 ◽  
Vol 51 (s3) ◽  
pp. 509s-511s ◽  
Author(s):  
I. McD. G. Stewart
Keyword(s):  
Myocardial Infarction ◽  
Term Treatment ◽  
Receptor Blocker ◽  
Receptor Blockade ◽  
Hypertensive Patients ◽  
Long Term Treatment ◽  
Significant Difference ◽  
Group A ◽  
Β Receptor

1. After some exclusions, 169 severe uncomplicated essential hypertensive patients presenting consecutively were divided into two groups according to their treatment. Of these, 121 had been given long-term treatment containing propranolol (PC group) and forty-eight had been treated with hypotensive agents excluding any β-receptor-blocker group, the non-β-receptor-blocker (NBB) group. 2. There were no significant differences in myocardial infarction risk factors between the two groups. 3. After a mean follow-up of 5·25 years, nine of the 121 subjects (7·5%) in the PC group had suffered first infarctions and fifteen of the forty-eight subjects (31%) in the NBB group, a significant difference (P < 0·01). 4. It was concluded that the presence of propranolol had prevented more or caused fewer infarctions, perhaps a combination of both, than had the older hypotensive agents unsupported by β-receptor blockade.

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.

A Comparison of the Acute Haemodynamic Effects of Propranolol and Pindolol at Rest and during Supine Exercise in Man

1980 ◽  
Vol 59 (s6) ◽  
pp. 465s-468s ◽  
Author(s):  
T. L. Svendsen ◽  
J. E. Carlsen ◽  
O. Hartling ◽  
A. McNair ◽  
J. Trap-Jensen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Response Curves ◽  
Receptor Blocking ◽  
Artery Pressure ◽  
Arterial Blood ◽  
Β Receptor

1. Dose-response curves for heart rate, cardiac output, arterial blood pressure and pulmonary artery pressure were obtained in 16 male patients after intravenous administration of three increasing doses of pindolol, propranolol or placebo. All patients had an uncomplicated acute myocardial infarction 6–8 months earlier. 2. The dose-response curves were obtained at rest and during repeated bouts of supine bicycle exercise. The cumulative dose amounted to 0.024 mg/kg body weight for pindolol and to 0.192 mg/kg body weight for propranolol. 3. At rest propranolol significantly reduced heart rate and cardiac output by 12% and 15% respectively. Arterial mean blood pressure was reduced by 9.2 mmHg. Mean pulmonary artery pressure increased significantly by 2 mmHg. Statistically significant changes in these variables were not seen after pindolol or placebo. 4. During exercise pindolol and propranolol both reduced cardiac output, heart rate and arterial blood pressure to the same extent. After propranolol mean pulmonary artery pressure was increased significantly by 3.6 mmHg. Pindolol and placebo did not change pulmonary artery pressure significantly. 5. The study suggests that pindolol may offer haemodynamic advantages over β-receptor-blocking agents without intrinsic sympathomimetic activity during low activity of the sympathetic nervous system, and may be preferable in situations where the β-receptor-blocking effect is required only during physical or psychic stress.

Controlled β-Receptor Blockade with Flestolol: A Novel Ultrashort-Acting β-Blocker

1987 ◽  
Vol 9 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Vishnubhakta S. Murthy ◽  
Tsae-Fung Hwang ◽  
Leon B. Rosen ◽  
Richard J. Gorczynski
Keyword(s):  
Receptor Blockade ◽  
Β Blocker ◽  
Β Receptor
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