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Biomedical subjects

C Wilhelmsson

Publications and source records attributed to C Wilhelmsson.

12 recordsLinked to original sources

Intrinsic sympathomimetic activity of penbutolol.

Six healthy volunteers took part in a randomized, single-blind, crossover study to quantitate the intrinsic sympathomimetic activity (ISA) of penbutolol in comparison with one drug possessing ISA (alprenolol) and with the standard non-ISA drug (propranolol). Single intravenous and one week oral administrations were studied. Complete parasympathetic and sympathetic isolation of the heart was obtained by administration of atropine 0.04 mg/kg body weight i.v. and propranolol 0.4 mg/kg i.v., or corresponding equipotent doses of alprenolol 0.4 mg/kg i.v. and penbutolol i.v. 0.08 mg/kg. In the chronic, oral study propranolol 160 mg b.i.d. was given, or corresponding equipotent doses of alprenolol (400 mg b.i.d.) or penbutolol (40 mg b.i.d.). The test procedure included measurement of heart rate and blood pressure in the supine, sitting and standing positions, and during isometric and dynamic exercise. ISA was calculated by comparison of the change in of heart rate with that produced by propranolol. The ISA of alprenolol was 22--26% and of penbutolol 12--18% of maximal sympathetic activity. Isometric and dynamic exercise gave comparable ISA values.

Adrenergic beta-Antagonists

Effects of labetalol and propranolol on blood pressure at rest and during isometric and dynamic exercise.

The influence of intravenous labetalol and propranolol on the blood pressure response to isometric and dynamic exercise was examined in a double blind study in eight, young, normotensive volunteers. Effects were recorded after propranolol 7.5, 15 and 30 mg i. v., and after labetalol 30, 60 and 120 mg i. v. In control experiments saline was administered. Mean blood pressure rose with successive handgrip tests following saline and propranolol, but not after labetalol, and the difference was significant. The total dose of each drug produced the same reduction in heart rate during sub-maximal bicycle exercise. The exercise-induced systolic blood pressure response did not differ between the drugs.

Adult

Influence of a myocardial infarction on blood pressure and serum cholesterol.

Blood pressure (BP) was measured before and after acute myocardial infarction (MI) in 21 men aged 49--60 years from a random population sample. Men on drugs affecting BP before MI or during follow-up were excluded. Pre- and postinfarction cholesterol levels were analyzed in 49 men not on hyperlipidemic treatment recruited from the same population sample. The mean fall in systolic BP (SBP) was 14 mmHg both five weeks and one year after the acute event, but 10 mmHg after two years. The mean fall in diastolic BP (DBP) was 10 mmHg five weeks after the MI and remained at this level for two years. The decreases in SBP and DBP were significant. There was a positive correlation between the maximum rise in SGOT during the acute phase of MI and the decrease in DBP between preinfarction readings and readings five weeks after the MI. Serum cholesterol was unchanged three months, and one and two years after the MI as compared to the preinfarction level.

Aged

QT time in patients treated with alprenolol or placebo after myocardial infarction.

Studies were made on the effects of long-term beta-blockade on the QT interval in patients discharged alive from hospital after myocardial infarction. The patients (n = 230) in this study constituted all those who participated in the alprenolol study on postmyocardial patients in Göteborg, Sweden. The study was double-blind (alprenolol 200 mg b.i.d. or placebo) and randomised. The patients were divided into 4 risk groups (1-4) with different predicted mortality. The electrocardiograms before and after 8 weeks of treatment were analysed with respect to heart rate and QT time. There was a decrease in heart rate of about 10% in the alprenolol treated patients. The QT time was not significantly influenced by alprenolol. The rate corrected QT time (QTc) decreased in the subgroup of the most severely diseased patients (subgroup 4) treated with alprenolol.

Aged

Effects of a new beta1-selective beta-blocker H 87/07 in angina pectoris.

The efficacy and toleration of a new beta1-selective beta-blocker, H 87/07, was compared with placebo in 33 patients with angina pectoris. The efficacy was evaluated using subjective assessments of attack rate and nitroglycerin consumption as well as objective assessments of exercise tolerance on a bicycle ergometer. H 87/07 significantly reduced the attack rate and the nitroglycerin consumption compared with placebo. The mean reduction amounted to 13 and 36% respectively. No significant differences were found between H 87/07 and placebo with regard to exercise tolerance. Due to high intrinsic stimulating activity (I.S.A.) H 87/07 altered the heart rate and blood pressure only slightly at rest but during exercise significant reductions were seen. Except for one patient who had cardiac decompensation on H 87/07 no side-effects of clinical importance were seen. No significant changes were seen with regard to the laboratory tests performed.

Adrenergic beta-Antagonists

Smoking and myocardial infarction.

In a representative series of male patients with primary myocardial infarction the prevalence of smokers prior to infarction was higher than in representative population samples. The difference decreased with increasing age, Those patients generally had a somewhat more severe clinical course than those who continued to smoke. Nevertheless, those who stopped had only half the rate of non-fatal recurrences (P smaller than 0.01) and half the cardiovascular mortality-rate (P smaller than 0.05) of those who continued to smoke.

Adult