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Biomedical subjects

G Kaik

Publications and source records attributed to G Kaik.

At least 19 recordsLinked to original sources

Assessment of systemic effects of different ophthalmic beta-blockers in healthy volunteers.

Systemic beta-blockade after single doses of ophthalmic beta-blockers (one drop in each eye) was investigated in healthy volunteers in two randomized, double-blind, crossover, placebo-controlled studies. beta-Blockade was evaluated by displacement of the bronchodilator (specific airway conductance), positive chronotropic (heart rate), and tremorogenic (finger tremor amplitude) dose-response curve for inhaled isoproterenol. In study 1, 0.5% betaxolol, 0.6% metipranolol, and 0.5% timolol were tested in 16 subjects. Compared with placebo, all beta-blockers resulted in a significant systemic beta-blockade (p greater than 0.05); the increasing order of potency was betaxolol, metipranolol, and timolol. In study 2, 2% butylamino-phenoxy-propanol-acetate (BPPA; a noncardioselective but topically oculoselective drug) and 1% timolol were investigated in 12 subjects. Placebo and BPPA showed no differences (p greater than 0.05), whereas timolol resulted in a significant beta-blockade (p less than 0.05). Topical oculoselectivity is an important aspect of drug safety of beta-blocking eyedrops. Measure of tremor is appropriate to evaluate beta 2-blockade.

Adrenergic beta-Antagonists

Pulmonary effects of long-term beta 2-blockade in healthy subjects: comparative study of metoprolol OROS.

The effects on airway response of metoprolol OROS (oral osmotic) and three other long-acting beta-adrenoceptor blockers were studied. This was a placebo-controlled, randomized, five-period, single-blind, crossover trial in 15 healthy volunteers. Bronchial beta-blockade was estimated as the displacement of the salbutamol bronchodilator response of specific airway conductance (SGAW) measured by whole-body plethysmography. Metoprolol OROS (14/190 mg), slow-release (SR) metoprolol (200 mg), atenolol (100 mg), long-acting (LA) propranolol (160 mg), and placebo were given once daily for 7 days. Inhaled salbutamol was administered at peak drug levels in cumulative doses of 12.5 to 800 micrograms on day 5 and in a single dose of 400 micrograms on day 7. On day 5, salbutamol induced significant increases in SGAW in each treatment group. SGAW increased after the single dose of salbutamol on day 7 in all groups and then declined steadily. The highest values were found after placebo and metoprolol OROS, with smaller increases after SR metoprolol, atenolol, and LA propranolol, the latter showing the smallest increase. Therefore, it would appear that under steady-state conditions, beta 2-bronchial receptors are least blocked by metoprolol OROS, followed by SR metoprolol, atenolol, and LA propranolol.

Administration, Oral

Dose related protective effect of azelastine on histamine induced bronchoconstriction in extrinsic asthma.

The effect of single oral doses of the antiallergic agent azelastine hydrochloride (1.1, 2.2 and 4.4 mg) was compared to placebo on airway response to histamine challenge in 12 asymptomatic extrinsic asthmatics with proven bronchial hyperresponsiveness to inhaled histamine in a randomized double-blind crossover trial. All doses of azelastine resulted in a significant protection compared to placebo. The effects of 2.2 and 4.4 mg were equivalent and superior compared to 1.1 mg. A naturally small but statistically significant bronchodilator effect was observed 4 h after the two higher doses of azelastine. Tiredness was reported by two patients, the symptom occurred following each placebo and the active drug.

Airway Resistance

[Clinico-pharmacologic study of a new sustained-release oral salbutamol preparation in patients with obstructive airway disease].

A new sustained release preparation of oral salbutamol (8 mg) was compared to salbutamol (8 mg) and placebo in 15 patients suffering from chronic obstructive airways disease in a randomized double-blind cross-over trial. Changes in airways resistance and amplitude of finger tremor as well as subjective assessment of side effects (tremors, unrest, palpitations) revealed a longer lasting effect following the sustained release preparation of salbutamol.

Adult

Cardioselectivity of cetamolol compared with atenolol and nadolol.

The selectivity of the beta-adrenoceptor blockade produced by single oral doses of cetamolol, atenolol, and nadolol was compared in normal male subjects. Study 1 established the dose at which each drug provides equivalent beta-1 blockade. Beta-1 blockade was estimated using the degree of inhibition of the increased heart rate (HR) response to graded exercise. Cetamolol (30 mg), atenolol (100 mg), and nadolol (80 mg) all attenuated the HR response to a comparable extent. This result established that the dose ratio of cetamolol:atenolol:nadolol of 1.00:3.33:2.67 provides equipotent beta-1 blockade. This ratio of doses was used in Studies 2 and 3 to evaluate the antagonism of beta-2-mediated responses to titrated doses of intravenous isoproterenol (ISO) by low and high doses of each drug. Beta-2 blockade was assessed using the attenuation of ISO-induced reductions in diastolic blood pressure (DBP) in Study 2 and ISO-induced increases in specific airway conductance (sGAW) in Study 3. For within drug comparisons, antagonism of the HR increase induced by ISO (a response mediated by both beta-1 and beta-2 receptors) was also examined. Treatments included cetamolol (15 and 60 mg), atenolol (50 and 200 mg), and nadolol (40 and 160 mg in Study 2; 40 mg only in Study 3). All drugs tested suppressed the HR, DBP, and sGAW responses to ISO, and this blockade was dose dependent. Cetamolol and nadolol produced approximately equipotent beta-1 blockade, whereas cetamolol at both doses produced a less potent beta-2 blockade. Atenolol antagonized ISO effects on all parameters less than either cetamolol or nadolol. Quantitative cardioselectivity indices revealed that cetamolol 60 mg was the most cardioselective and nadolol 40 mg the least. Data from the three studies demonstrate that cetamolol is cardioselective relative to nadolol and that, in contrast to atenolol, cardioselectivity appears to increase at the higher dose.

Acetamides

[A double blind cross-over study with mepindolol-sulfate in patients with coronary heart disease (author's transl)].

UNLABELLED: The effect of mepindolol-sulfate (2 x 2.5 mg) was tested in 20 patients with coronary heart disease in a controlled study against placebo resp. propranolol (3 x 40 mg). RESULTS: 1. The frequency and intensity of anginal attacks were reduced significantly under mepindolol-sulfate therapy.-- 2. There was a significant improvement of ergometric exercise tolerance under mepindolol-sulfate therapy.--3. Additionally a reduction of ST-depression in ECG was found under mepindolol-sulfate.--4. In patients with coronary heart disease the clinical effect of mepindolol-sulfate in a daily dose of 2 x 2.5 mg was equal to propranolol in a daily dose of 3 x 40 mg.

Adrenergic beta-Antagonists

[Digitalis therapy in practice: correlation between clinical evaluation and plasma digoxin concentration (author's transl)].

In a prospective study 73 patients on maintenance digitalis treatment at the Paracelsus Institute, Bad Hall, were clinically examined and the dosage of the drug was adjusted according to cardiac symptoms. The clinical effects were correlated to digoxin concentrations measured on the day following admission to hospital and on the 21st day of treatment. The following practical conclusions were reached: 1. More than 50% of the patients were underdigitalized. 2. There is often no indication for digitalis therapy in patients with a low daily maintenance digoxin dosage and normal renal funciton. 3. The usual recommended maintenance dosage of digoxin provides serum digoxin levels in the lower region of the therapeutic range. 4. Patients with symptoms of decompensation taking an average dosage of digoxin need more digitalis. There is generally no danger of toxicity when the dosage is increased. 5. The serum digoxin concentration in patients with slightly reduced renal function lies in the upper region of the therapeutic range with usual doses of digoxin.

Arrhythmias, Cardiac

Effect of calculation stress on hemodynamics and plasma catecholamines before and after beta-blockade with propranolol (Inderal) and mepindolol sulfate (Corindolan).

The effect of calculation stress on hemodynamic parameters and plasma adrenalin and noradrenalin was studied in two groups of 6 male subjects, before and during beta-Blockade. One group received propranolol 15 mg i.v. and the other received mepindolol sulphate 0,5 mg i.v. There was an increase in heart rate, cardiac output and blood pressure during mental stress. A significant increase in plasma adrenalin but not in noradrenalin occurred at the same time. The stress-induced rise in HR but not that in blood pressure could be prevented by beta-receptor blockage with propranolol and mepindolol sulfate. The peripheral resistance (PR) and diastolic blood pressure in stress were even higher after propranolol than in the control study. Propranolol had no effect on the increased adrenalin concentration during stress, but it was prevented by mepindolol sulfate. There was no correlation between the increase in HR and that in adrenalin during stress, but the HR in stress and the HR reaction to infused isoproterenol were highly correlated.

Blood Pressure

[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

[Hemodynamics in patients suffering from hyperkinetic cardiac syndromes and in normal persons under psychological stress before and after treatment with propranolol (author's transl)].

In patients with hyperkinetic heart syndrome we found at rest a higher heart rate, a higher stroke volume and a higher cardiac output than in normal volunteers. Therefore blood pressure is high although peripheral resistance is lower than in normals. Similar circulatory differences were found under conditions of mental stress. After beta-adrenergic blockade with 15 mg Propranolol heart rate and cardiac output decrease, whereas peripheral resistance increases. Mean blood pressure thus remains unchanged. Even after beta-adrenergic blockade circulatory differences between normals and patients with hyperkinetic heart syndrome are seen. The possible causes of these differences are discussed.

Blood Pressure

Hemodynamic changes in hypertensive patients at rest and during physical exercise before and after acute i.v. administration of bufuralol-HCl or propranolol.

The hemodynamic effects of 20 mg Bufuralol-HCl and of 15 mg Propranolol given to hypertensives i.v. at rest and under physical exercise conditions were examined. It could be shown that Bufuralol-HCl lowered the diastolic BP and PR at rest already in the acute experiment, contrary to Propranolol. Under physical exercise conditions the diastolic BP is lowered, the PR remains unchanged in spite of reduced CO. After exclusion of other possible explanations, Bufuralol-HCl may lower the diastolic BP acutely at least partly by inhibition of cerebral beta-receptors. A faster and better liquor diffusion could be the reason for these results. It can be assumed that the acute BP lowering effect is mediated by the same mechanism as the chronic effect of the other beta-receptor blocking drugs.

Adrenergic beta-Antagonists

Hemodynamic characterization of bufuralol-HCl and pindolol based on the competitive effects of isoproterenol.

In this hemodynamic study a new beta-receptor blocker, Bufuralol-hydrochloride was compared with Pindolol under an Isoproterenol infusion with increasing doses in healthy male volunteers. We found the following results: 1. Before Isoproterenol peripheral resistance increased after acute i.v. application of Pindolol but decreased after Bufuralol-hydrochloride i.v. application. 2. After beta-receptor blockade with either Bufuralol-hydrochloride or with Pindolol a shift to the right of the dose effect relationship concerning heart rate and cardiac output under Isoproterenol infusion was observed, indicating beta 1-blockade. 3. The reduction of peripheral resistance which is usually observed as a sign of beta 2-blockade was also shifted to the right under the influence of both drugs. 4. This proves Bufuralol-hydrochloride to be a non-specific beta-blocking agent with an affinity to the beta 1- and beta 2-receptors. 5. Although Bufuralol-hydrochloride has a beta 2-blocking property which is even more pronounced than that of Pindolol, it reduces acutely, intravenously given, peripheral resistance.

Adrenergic beta-Antagonists

[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