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Biomedical subjects

G Hitzenberger

Publications and source records attributed to G Hitzenberger.

At least 91 records · Page 5Linked to original sources

Pharmacokinetic comparison of etilefrine to its prodrug, the stearic acid ester of etilefrine.

The relative bioavailability of a prodrug of etilefrine, its stearic acid ester, was determined by means of plasma levels and renal excretion. The comparison of the plasma levels and renal excretion was carried out in a cross-over design in six subjects. 3H-etilefrine (20 mg) and 3H-2-etylamino-1-(3-stearoylphenyl)ethanol hydrochloride (44.42 mg) were administered orally in equimolecular amounts. The stearic acid ester of etilefrine does not appear in the blood; the ester is split even during absorption. The relative bioavailability of the stearic acid ester of etilefrine, which was determined from the comparison of the areas under the plasma level and the renal excretion, amounts to 51% related to etilefrine. The investigation of the renal excretory products after administration of etilefrine and its prodrug showed the same metabolic pattern. The sulfuric acid ester of etilefrine is the main metabolite. In addition to etilefrine, two basic metabolites are excreted. According to mass- and NMR-spectrometric findings, these two metabolites are two isomeric tetrahydroisoquinolines which formally developed by condensation of etilefrine with formaldehyde. These tetrahydroisoquinolines are excreted free and conjugated with sulfuric acid.

Adult↗

Pharmacokinetics and pharmacodynamics of mepindolol sulphate.

Five clinically healthy, male volunteers were each given an intravenous dose of 1.19 mg of 2-methyl-14C-mepindolol sulphate, followed one week later by an oral dose of 20 mg. In addition, the effect of mepindolol sulphate was studied in 3 male test subjects after repeated oral administration for 8 days with a daily dose of 2 x 2.5 mg using the heart rate behaviour model during submaximum ergometer exercise. Synchronously with pharmacodynamics, pharmacokinetic data were also obtained after multiple dosing.

Administration, Oral↗

[New antibiotics].

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Aminoglycosides↗

[Biological availability of spironolactone in two different galenic forms (author's transl)].

The biological availability of spironolactone in two different galenic preparations (Spiro-Tablinen and Aldactone-100 Caps) was investigated in a single-blind, randomised, cross-over study in six healthy probands. The serum concentration of canrenone after oral intake of spironolactone (100 mg) was investigated in the steady state as well as the renal excretion of canrenone. There were no statistically significant differences between the two preparations either in the course of the serum concentration of canrenone or in the cumulative renal excretion.

Adult↗

Initial experience with a new long-acting beta-blocker, nadolol, in hypertensive patients.

Nadolol, a new beta-blocker that is not metabolized and has a uniquely long pharmacological half-life (up to 24 hours) was employed as the sole drug therapy for thirty-one patients with mild to moderately severe essential hypertension. Twenty-two patients had a reduction over 3 months of 10% or more in supine diastolic pressure, including twelve who became normotensive. Daily dosage, administered in two divided doses, ranged up to 640 mg; however, twenty patients required 160 mg or less. Twenty-three patients continued therapy for a median additional period of 15 months, during which satisfactory control was maintained in seventeen patients. Side-effects of nadolol caused termination of therapy in only one patient.

Adrenergic beta-Antagonists↗

[Pulmonary function tests with the bronchodilator Terbutaline].

The acute bronchodilator effect of the beta 2-adrenoceptor agonist terbutaline was tested single-blind cross-over in out-patients with chronic obstructive airways disease (intrinsic asthma). In 7 series comparisons were made with other marketed bronchodilators. Airways resistance was measured by whole body plethysmography. In another 3 series the effect on heart rate of terbutaline and other adrenocepter agonists was tested in healthy volunteers. Terbutaline and the adrenoceptor agonists clenbuterol, epinephrine, fenoterol, hexoprenaline, isoprenaline, metaproterenol, reproterol and salbutamol, the vagolytics atropine, ipratropium bromide and AA 22-263, the xanthinederivative theophylline ethylenediamine and one combined substance drug were used.

Administration, Oral↗

[Lung function studies with the bronchodilator terbutaline].

The acute bronchodilator effect of the beta 2-adrenoceptor agonist terbutaline was tested single-blind cross-over in out-patients with chronic obstructive airways disease (intrinsic asthma). In 7 series comparisons were made with other marketed bronchodilators. Airways resistance was measured by whole body plethysmography. In another 3 series the effect on heart rate of terbutaline and other adrenoceptor agonists was tested in healthy volunteers. Terbutaline and the adrenoceptor agonists clenbuterol, epinephrine, fenoterol, hexoprenaline, isoprenaline, metaproterenol, reproterol and salbutamol, the vagolytics atropine, ipratropium bromide and AA 28-263, the xanthine-derivative theophylline ethylenediamine and one combined substance drug were used.

Adult↗

[Haemodynamic characterization of a new beta-receptor blocker celiprolol (st1396) at rest and during ergometer exercise compared with propranolol (inderal) (author's transl)].

A new beta-receptor blocker (Celiprolol) was characterized in man by haemodynamic studies carried out on a random cross-over basis in 6 volunteers before and after intravenous administration of the drug or propranolol. The studies were performed at rest and in response to ergometer exercise. The studies showed that: 1. Celiprolol is a cardio-selective beta-receptor blocker with pronounced intrinsic sympathomimetic activity. Hence, Celiprolol increases the heart rate and cardiac output at rest. 2. The heart rate was reduced by Celiprolol during pronounced physical exercise. 3. Celiprolol probably has only a very slight blocking effect on those, beta1-receptors which mediate a positive inotropic effect. 4. The increase in blood pressure during exercise was less pronounced during Celiprolol medication than with propranolol.

Adrenergic beta-Antagonists↗

Decrease of peripheral resistance after acute intravenous application of a new beta-receptor blocking agents, bufuralol HCl.

The hemodynamic effects of a new beta-receptor blocking agent, bufuraolo HCl, were compared with those of pindolol. Contrary to pindolol, bufuralol HCl induces a decrease of the peripheral resistance immediately. Under exercise conditions, the peripheral resistance increases under pindolol whereas it remains constant under bufuralol HCl in spite of reduced cardiac output. As an explanation, an effect of bufuralol HCl on peripheral resistance is discussed which might be independent of the beta-receptor blocking effects in the periphery.

Adrenergic beta-Antagonists↗

[Hemodynamics in patients with coronary heart disease under conditions of physical exercise before and after mepindolol-sulfate (author's transl)].

UNLABELLED: The effect of exercise upon hemodynamic variables was investigated in seven patients with coronary artery disease during an eight-week double blind cross-over study with placebo and with mepindolol-sulfate, a new beta-receptor blocking agent. RESULTS: 1. The first hemodynamic sign of myocardial ischemia during exercise was an increase of pulmonary capillary pressure in parallel with ST-segment depression in the Ecg. 2. Angina was accompanied by a fall of the stroke volume and an increase of the peripheral resistance. 3. During beta-receptor blockade with mepindolol-sulfate angina was compensated, the unfavourable hemodynamic effects seen during placebo did not occur. 4. No signs of congestive heart failure were found during mepindolol-sulfate-therapy. 5. Mepindolol-sulfate showed a pronounced blood-pressure lowering effect.

Aged↗

[Hemodynamic differences in the effects of mepindolol-sulfate and propranolol after 4 weeks treatment under conditions of rest and physical exercise in patients with coronary heart disease (author's transl)].

UNLABELLED: The hemodynamic effect of mepindolol-sulfate, a new non-cardioselective beta-receptor blocking agent, was compared with the hemodynamic effect of propranolol at rest and during exercise in five patients with coronary artery disease during an eight week double blind cross-over study. RESULTS: 1. The beta-receptor blocking effect of mepindolol-sulfate is 25 times higher than that of propranolol. 2. No hemodynamic difference between mepindolol-sulfate and propranolol was seen at rest. 3. The increase of blood pressure during exercise was less pronounced during mepindolol-sulfate-medication compared to propranolol. 4. Propranolol seems to achieve a more pronounced negative inotropic effect than mepindolol-sulfate.

Aged↗

Effect of exercise and of prolonged oral administration of propranolol on haemodynamic variables, plasma renin concentration, plasma aldosterone and c-AMP.

The effect of submaximal exercise upon haemodynamic and biochemical variables was investigated in healthy male subjects, aged 17-27 years, before and at the end of 2 weeks treatment with propranolol (40 mg p.o., q.i.d.). Propranolol reduced the resting blood pressure in normal subjects significantly. This effect was due to reduction of cardiac output and of systemic vascular resistance. No effect of propranolol on BP was seen during maximal exercise, since a reduced cardiac output was accompanied by an increased peripheral resistance. The reduction of cardiac output during exercise can be compensated in part by an increase in stroke volume. The sympathetic activity induced by physical exercise in normotensives increased plasma renin concentration (PRC) and plasma aldosterone (PA), and suppressed urinary excretion of c-AMP. PRC returned to basal levels after 45 min. No increase of PRC was observed after exercise in subjects treated with propranolol. Yet the increase of PA was not completely suppressed. No direct relation was demonstrated between PRC and the haemodynamic variables before or during the administration of propranolol.

Administration, Oral↗