ABSTRACT
Betaxolol, a new beta-receptor blocking drug administered as a single dosage of 40 mg given orally, causes a maximal reduction of heart rate at rest of 30%, during a submaximal exercise of 28% and at rest after exercise of 33%. The reduction in heart rate is still highly significant 48 hours after administration at rest, during exercise as well after administration. A smaller but still significant reduction in heart rate was found after the oral administration of 20 mg of betaxolol. Betaxolol appears to be more effective than a single oral dose of 160 mg of long-acting propranolol. No significant differences were found between 9 submaximal exercise tests performed within a period of 50 hours in normal subjects.
Subject(s)
Adrenergic beta-Antagonists/pharmacology , Heart Rate/drug effects , Propanolamines/pharmacology , Adult , Betaxolol , Humans , Male , Physical Exertion , RestABSTRACT
A 52 years old woman with mitral valve prolapse and a history of 3 cardiac syncopes occurring during antiarrhythmic therapy underwent mitral valve replacement. Antiarrhythmic drugs had to be continued postoperatively but no major ventricular arrhythmias occurred after surgery.
Subject(s)
Arrhythmias, Cardiac/etiology , Mitral Valve Prolapse/complications , Anti-Arrhythmia Agents/therapeutic use , Arrhythmias, Cardiac/drug therapy , Electrocardiography , Female , Heart Valve Prosthesis , Heart Ventricles , Humans , Middle Aged , Mitral Valve Prolapse/diagnosis , Mitral Valve Prolapse/surgeryABSTRACT
1. The anti-hypertensive effect of atenolol was greater than that of bendrofluazide. 2. The change in systolic blood pressure caused by bendrofluazide showed a significant inverse correlation iwth the plasma renin concentration (r=-0-47; P less than 0-01). 3. The correlation between the change in systolic blood pressure caused by atenolol and the plasma renin concentration was not significant (r =0-28; 0-1 greater than P greater than 0-05). 4. Plasma renin concentration was unaffected by atenolol.
Subject(s)
Antihypertensive Agents/therapeutic use , Atenolol/therapeutic use , Bendroflumethiazide/therapeutic use , Propanolamines/therapeutic use , Renin/blood , Clinical Trials as Topic , Humans , Hypertension/drug therapyABSTRACT
Fifty-five patients with mild to moderate, renal or essential hypertension were admitted to a double blind cross-over trial of 18 weeks, involving treatment periods with placebo, the thiazide bendrofluazide (15 mg daily) and the beta blocker atenolol (600 mg daily). Compared to the placebo period (190/117 mm Hg) the hypotensive effect of atenolol (-24/16 mm Hg) was more pronounced than the hypotensive effect of bendrofluazide (-17/6 mm Hg). Arguments in favor of initiating antihypertensive drug therapy with beta blocker were its more powerful hypotensive effect, the quicker onset of its action, less metabolic disturbance, decreased frequency of complaints and patient's preference. On thiazides body weight and the frequency of swollen ankles decreased. Plasma renin concentration was not found to have a strong predicting power for the hypotensive effect of atenolol or bendrofluazide but low renin patients showed a more pronounced blood pressure decrease on bendrofluazide and high renin patients, especially essential hypertensives, on atenolol. While these points can be a guide to therapy today, the preference of one drug over the other must eventually be based on their relative efficacy in decreasing morbidity and mortality from the hypertensive disease.
Subject(s)
Adrenergic beta-Antagonists/therapeutic use , Atenolol/therapeutic use , Bendroflumethiazide/therapeutic use , Hypertension/drug therapy , Propanolamines/therapeutic use , Adrenergic beta-Antagonists/adverse effects , Adult , Atenolol/adverse effects , Bendroflumethiazide/adverse effects , Clinical Trials as Topic , Drug Evaluation , Female , Humans , Hypertension, Renal/drug therapy , Male , Patient Compliance , PlacebosABSTRACT
The antihypertensive effect of the new beta-blocker, ICI 66,082 was studied in 37 patients with renal or essential hypertension. A daily dose of 75 mg produced a significant antihypertensive effect and a further blood pressure decrease was obtained by increasing the daily dose up to 300 mg; at this treatment level, the antihypertensive effect averaged 29.4/24.0 mm Hg. Increasing the dose from 300 to 600 mg daily did not produce a significant additional blood pressure decrease. Six of the 37 patients retained fluid, producing a loss in the antihypertensive effect. No significant correlation was found between the percentage systolic blood pressure fall and the following parameters determined before therapy: systolic blood pressure and its variability, heart rate (at rest and after stimulation by exercise or isoproterenol), cardiac output and total peripheral resistance, renin concentration (at rest and after stimulation) and urinary excretion of catecholamines and derivates.
