Xamoterol

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Else Vigholt Sorensen - One of the best experts on this subject based on the ideXlab platform.

  • renal effects of Xamoterol in patients with moderate heart failure
    Cardiovascular Drugs and Therapy, 1993
    Co-Authors: Hans Erik Botker, Henrik Jensen, Lars Romer Krusell, Else Vigholt Sorensen
    Abstract:

    The acute renal effects of Xamoterol, a partial beta1-agonist, were studied in 12 patients with congestive heart failure (NYHA II–III) in stable condition on diuretic therapy for at least 6 weeks. Each patient was given a single intravenous infusion of Xamoterol (0.2 mg/kg) or placebo in random order 2 weeks apart. Using constant infusion and lithium clearance techniques, clearance and excretion measurements were made in the supine position at 30- to 60-min intervals before, during, and up to 6 hours after infusion. Blood pressure, heart rate, renal plasma flow, glomerular filtration rate, and urinary flow rate remained unchanged, but Xamoterol lowered sodium excretion by 30% (p<0.05). The decrease started 120 minutes after infusion. Proximal reabsorption of sodium increased after Xamoterol infusion, whereas plasma values of aldosterone and angiotensin II were unaffected. It is concluded that the acute renal effects of Xamoterol imply an impaired sodium excretion determined by the tubular actions of the drug. The present results suggest that Xamoterol may aggravate one of the important abnormalities intrinsic to the pathology of congestive heart failure. These findings are in contrast to the beneficial effects of Xamoterol demonstrated in many clinical trials where Xamoterol was given orally for a longer period.

  • Renal effects of Xamoterol in patients with moderate heart failure
    Cardiovascular Drugs and Therapy, 1993
    Co-Authors: Hans Erik Botker, Lars Romer Krusell, Henrik Kjærulf Jensen, Else Vigholt Sorensen
    Abstract:

    The acute renal effects of Xamoterol, a partial beta_1-agonist, were studied in 12 patients with congestive heart failure (NYHA II–III) in stable condition on diuretic therapy for at least 6 weeks. Each patient was given a single intravenous infusion of Xamoterol (0.2 mg/kg) or placebo in random order 2 weeks apart. Using constant infusion and lithium clearance techniques, clearance and excretion measurements were made in the supine position at 30- to 60-min intervals before, during, and up to 6 hours after infusion. Blood pressure, heart rate, renal plasma flow, glomerular filtration rate, and urinary flow rate remained unchanged, but Xamoterol lowered sodium excretion by 30% (p

Jens Trap-jensen - One of the best experts on this subject based on the ideXlab platform.

  • Xamoterol, a New Selective β-1-Adrenoceptor Partial Agonist, in the Treatment of Postural Hypotension
    Acta medica Scandinavica, 2009
    Co-Authors: J. Mehlsen, Jens Trap-jensen
    Abstract:

    ABSTRACT. Three patients severely disabled from postural hypotension were treated with Xamoterol, a selective β-1-adrenoceptor antagonist with a high degree of partial agonist activity. Oral treatment (200 mg b.i.d.) was chosen on the basis of the effects of acute intravenous administration of Xamoterol and pindolol, a non-selective β-adrenoceptor antagonist with partial agonist activity. In these patients pindolol had a predominantly antagonist effect, whereas Xamoterol had a predominantly agonist effect after intravenous administration. Oral treatment was carried out with placebo control in a single-blind fashion. The patients reported gradual improvement during the first days of treatment. After 1 month of oral treatment, heart rate had increased by 15 beats/min, systolic blood pressure from 131 to 170 mmHg, diastolic blood pressure from 77 to 91 mmHg and mean blood pressure by 22 mmHg (mean values, supine). During the placebo period (2 weeks) heart rate decreased to pretreatment levels and mean blood pressure was reduced by only 14 mmHg. The patients reported substantial improvement in their condition during active medication. Xamoterol seems to be a useful alternative in the treatment of postural hypotension.

  • Xamoterol in severe congestive heart failure: long-term oral treatment, a double-blind randomised study.
    International journal of cardiology, 1992
    Co-Authors: M. Tangø, K. Lyngborg, Jesper Mehlsen, Jens Trap-jensen
    Abstract:

    Abstract Twelve patients in severe congestive heart failure were given placebo, 100 mg Xamoterol (Corwin ® ) twice daily and 200 mg Xamoterol twice daily, respectively, in 3 two-week periods in a double-blind randomised study. At the end of each treatment period the patients were evaluated. No differences were found between placebo and Xamoterol in the following parameters: New York Heart Association function group index, heart volume, body weight, exercise duration on bicycle and treadmill, heart rate and systolic and diastolic blood pressure at rest. However, during exercise we found significantly lower heart rate and rate-pressure product during Xamoterol treatment. This reduction is probably indicating occupation of β-adrenoreceptors with concomitant reduced oxygen consumption during exercise.

P Dorigo - One of the best experts on this subject based on the ideXlab platform.

  • in vitro evidence that carteolol is a nonconventional partial agonist of guinea pig cardiac β1 adrenoceptors a comparison with Xamoterol
    Journal of Pharmacology and Experimental Therapeutics, 2005
    Co-Authors: Maura Floreani, Guglielmina Froldi, Luigi Quintieri, Katia Varani, Maria Teresa Dorigo, Pier Andrea Borea, P Dorigo
    Abstract:

    The present study was designed to verify our previous hypothesis that carteolol, a β1/β2-adrenoceptor-blocking agent, is a nonconventional partial agonist of cardiac β1-adrenoceptors. To this purpose, we characterized the effects of carteolol in guinea pig myocardial preparations and measured the affinities of carteolol for high- and low-affinity sites of β1-adrenoceptors labeled by CGP12177 [(–)4-(3- t -butylamino-2-hydroxypropoxy)-2-benzimidazol-2-one]. All experiments were performed in comparison with Xamoterol, a cardioselective β1-adrenoceptor partial agonist. Both drugs caused cAMP-dependent positive inotropic and chronotropic effects, but carteolol was less effective and less potent than Xamoterol, and its cardiac actions were not affected by conventional concentrations of the β-blocker propranolol. Both carteolol and Xamoterol antagonized the cardiac effects of isoprenaline, but although the antagonistic concentrations of Xamoterol were almost equal to those producing cardiostimulation, the antagonistic concentrations of carteolol were 3 log units lower than those causing cardiostimulant effects. Both carteolol and Xamoterol competed with (–)[3H]CGP12177 for a high-affinity site of β1-adrenoceptors, but carteolol showed a higher affinity than Xamoterol. Moreover, carteolol, unlike Xamoterol, bound also to a low-affinity site of the receptors. The binding affinity constants of the drugs for the high-affinity site correlated well with the respective blocking potencies against isoprenaline, whereas the affinity constant of carteolol for the low-affinity site was well related to its agonist potency. In conclusion, our findings demonstrate that carteolol, unlike Xamoterol, is a nonconventional partial agonist, which causes agonistic effects through interaction with the low-affinity propranolol-resistant site of β1-adrenoceptors and antagonistic actions through the high-affinity site of the same receptors.

  • In Vitro Evidence That Carteolol Is a Nonconventional Partial Agonist of Guinea Pig Cardiac β1-Adrenoceptors: A Comparison with Xamoterol
    The Journal of pharmacology and experimental therapeutics, 2005
    Co-Authors: Maura Floreani, Guglielmina Froldi, Luigi Quintieri, Katia Varani, Maria Teresa Dorigo, Pier Andrea Borea, P Dorigo
    Abstract:

    The present study was designed to verify our previous hypothesis that carteolol, a beta1/beta2-adrenoceptor-blocking agent, is a nonconventional partial agonist of cardiac beta1-adrenoceptors. To this purpose, we characterized the effects of carteolol in guinea pig myocardial preparations and measured the affinities of carteolol for high- and low-affinity sites of beta1-adrenoceptors labeled by CGP12177 [(-)4-(3-t-butylamino-2-hydroxypropoxy)-2-benzimidazol-2-one]. All experiments were performed in comparison with Xamoterol, a cardioselective beta1-adrenoceptor partial agonist. Both drugs caused cAMP-dependent positive inotropic and chronotropic effects, but carteolol was less effective and less potent than Xamoterol, and its cardiac actions were not affected by conventional concentrations of the beta-blocker propranolol. Both carteolol and Xamoterol antagonized the cardiac effects of isoprenaline, but although the antagonistic concentrations of Xamoterol were almost equal to those producing cardiostimulation, the antagonistic concentrations of carteolol were 3 log units lower than those causing cardiostimulant effects. Both carteolol and Xamoterol competed with (-)[3H]CGP12177 for a high-affinity site of beta1-adrenoceptors, but carteolol showed a higher affinity than Xamoterol. Moreover, carteolol, unlike Xamoterol, bound also to a low-affinity site of the receptors. The binding affinity constants of the drugs for the high-affinity site correlated well with the respective blocking potencies against isoprenaline, whereas the affinity constant of carteolol for the low-affinity site was well related to its agonist potency. In conclusion, our findings demonstrate that carteolol, unlike Xamoterol, is a nonconventional partial agonist, which causes agonistic effects through interaction with the low-affinity propranolol-resistant site of beta1-adrenoceptors and antagonistic actions through the high-affinity site of the same receptors.

D. G. Waller - One of the best experts on this subject based on the ideXlab platform.

  • Xamoterol improves right ventricular systolic and diastolic function in pulmonary heart disease.
    European journal of clinical pharmacology, 1996
    Co-Authors: R M Oliver, J S Fleming, D. G. Waller
    Abstract:

    Abnormal right ventricular function in patients with pulmonary heart disease (PHD) may contribute to their reduced exercise capacity. We have evaluated the effect of subacute dosing with Xamoterol, a beta-1 adrenoreceptor partial agonist with inotropic properties, on right ventricular function in patients with PHD. Twelve patients with advanced chronic obstructive pulmonary disease and clinical evidence of PHD received Xamoterol 200 mg twice daily or placebo for 7 days in a randomised double-blind crossover study. Right heart krypton-81m radionuclide ventriculography was used to derive right ventricular ejection fraction (RVEF) both at rest and during submaximal exercise, and indices of right ventricular systolic and diastolic function at rest. During treatment with placebo, mean RVEF was 0.53 at rest and was unchanged during exercise. After Xamoterol, mean RVEF was 0.55 at rest and increased to 0.59 during exercise. Xamoterol increased right ventricular peak ejection rate from 3.04 to 3.45 EDV.s-1 and mean early diastolic filling rate from 1.00 to 1.20 EDV.s-1. Subacute treatment with Xamoterol in patients with PHD improves right ventricular systolic and diastolic function at rest and results in a favourable augmentation in right ventricular function during submaximal exercise.

Hans Erik Botker - One of the best experts on this subject based on the ideXlab platform.

  • renal effects of Xamoterol in patients with moderate heart failure
    Cardiovascular Drugs and Therapy, 1993
    Co-Authors: Hans Erik Botker, Henrik Jensen, Lars Romer Krusell, Else Vigholt Sorensen
    Abstract:

    The acute renal effects of Xamoterol, a partial beta1-agonist, were studied in 12 patients with congestive heart failure (NYHA II–III) in stable condition on diuretic therapy for at least 6 weeks. Each patient was given a single intravenous infusion of Xamoterol (0.2 mg/kg) or placebo in random order 2 weeks apart. Using constant infusion and lithium clearance techniques, clearance and excretion measurements were made in the supine position at 30- to 60-min intervals before, during, and up to 6 hours after infusion. Blood pressure, heart rate, renal plasma flow, glomerular filtration rate, and urinary flow rate remained unchanged, but Xamoterol lowered sodium excretion by 30% (p<0.05). The decrease started 120 minutes after infusion. Proximal reabsorption of sodium increased after Xamoterol infusion, whereas plasma values of aldosterone and angiotensin II were unaffected. It is concluded that the acute renal effects of Xamoterol imply an impaired sodium excretion determined by the tubular actions of the drug. The present results suggest that Xamoterol may aggravate one of the important abnormalities intrinsic to the pathology of congestive heart failure. These findings are in contrast to the beneficial effects of Xamoterol demonstrated in many clinical trials where Xamoterol was given orally for a longer period.

  • Renal effects of Xamoterol in patients with moderate heart failure
    Cardiovascular Drugs and Therapy, 1993
    Co-Authors: Hans Erik Botker, Lars Romer Krusell, Henrik Kjærulf Jensen, Else Vigholt Sorensen
    Abstract:

    The acute renal effects of Xamoterol, a partial beta_1-agonist, were studied in 12 patients with congestive heart failure (NYHA II–III) in stable condition on diuretic therapy for at least 6 weeks. Each patient was given a single intravenous infusion of Xamoterol (0.2 mg/kg) or placebo in random order 2 weeks apart. Using constant infusion and lithium clearance techniques, clearance and excretion measurements were made in the supine position at 30- to 60-min intervals before, during, and up to 6 hours after infusion. Blood pressure, heart rate, renal plasma flow, glomerular filtration rate, and urinary flow rate remained unchanged, but Xamoterol lowered sodium excretion by 30% (p