Directional transcellular transport of bisoprolol in P-glycoprotein-expressed LLC-GA5-COL150 cells, but not in renal epithelial LLC-PK1 Cells.
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To evaluate the mechanism responsible for the tubular secretion of bisoprolol, we compared transcellular transport of bisoprolol with that of tetraethylammonium (TEA), cimetidine, and quinidine across LLC-PK1 cell monolayers grown on porous membrane filters. TEA and cimetidine were actively transported in the basolateral-to-apical direction by the specific transport system. Pharmacokinetic analysis indicated that basolateral influx and apical efflux were cooperatively responsible for the directional transport of TEA and cimetidine. Lipophilic cationic drugs, quinidine, S-nicotine, and bisoprolol, significantly diminished basolateral influx and apical efflux clearance of cimetidine. However, transcellular transport of quinidine in the basolateral-to-apical direction was similar to that in the opposite direction in LLC-PK1 cells. In contrast, quinidine was transported actively in the basolateral-to-apical direction in P-glycoprotein-expressed LLC-GA5-COL150 cells. Pharmacokinetic analysis indicated that P-glycoprotein increased the apical efflux of quinidine and also decreased the apical influx of the drug. Basolateral-to-apical transport of bisoprolol was also similar to apical-to-basolateral transport in LLC-PK1 cells, whereas the drug was directionally transported from the basolateral to the apical side in LLC-GA5-COL150 cells. These results suggested that bisoprolol was not significantly transported via transport systems involved in the directional transport of TEA and cimetidine, but that P-glycoprotein was responsible for the directional transport of bisoprolol as well as quinidine in renal epithelial cells. (+info)
A new liquid chromatography-tandem mass spectrometry method for determination of bisoprolol in human plasma samples.
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Beta-blocker treatment of stable heart failure in primary care.
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INTRODUCTION AND OBJECTIVES: Beta-blocker treatment of stable heart failure in primary care. The objective was to evaluate the feasibility and tolerability of uptitrating beta-blockers in patients with stable systolic heart failure seen in primary care. METHODS: Before and after intervention study. The study was conducted in two primary care centers in Barcelona, Spain. Consecutive samples of patients with systolic heart failure who had not received previous beta-blocker treatment were recruited between April 2004 and April 2006. Treatment was started with the lowest dose of bisoprolol or carvedilol and the dose was doubled every two weeks in the absence of contraindications. Patients were followed up for 6 months. RESULTS: The study included 88 patients (76.1% male, 23,9% female, mean age 64.88 years). Of these, 57.1% were treated with bisoprolol and 42.9% with carvedilol. Overall, 75.0% reached the target dose, 21.7% tolerated a dose lower than the target dose, and 3.3% had the beta-blocker withdrawn (due to bradycardia in 1.1%, syncope in 1.1%, and stroke in 1.1%). Adverse events were experienced by 70.4%, the majority of which (57.95%) were resolved without changing treatment. The most common were nausea (42.04%), asthenia (35.22%), and increased dyspnea (17.04%). There were significant improvements in functional class and ejection fraction. CONCLUSIONS: The majority of adverse events were mild. Treatment was withdrawn in only a few patients and most reached the recommended target dose. Appropriately trained primary care physicians can uptitrate beta-blockers in heart failure patients without undue concern. (+info)
Differential regulation of human cardiac beta-adrenergic and muscarinic receptors by chronic beta-adrenoceptor antagonist treatment.
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In patients undergoing coronary artery bypass grafting chronic beta 1-adrenoceptor antagonist treatment increased right atrial beta 1-adrenoceptor number, did not affect beta 2-adrenoceptor number and decreased muscarinic M2-receptor number. Concomitantly, the M2-receptor-mediated negative inotropic effect of carbachol was reduced, while the beta 1-adrenoceptor-mediated positive inotropic effect of noradrenaline was not altered. The beta 2- adrenoceptor mediated positive inotropic effect of procaterol, however, was markedly enhanced. We conclude that chronic beta 1-adrenoceptor antagonist treatment increases beta 1-adrenoceptor number, sensitizes beta 2-adrenoceptor function and desensitizes M2-receptor function in the human heart. (+info)
Prevention of myofilament dysfunction by beta-blocker therapy in postinfarct remodeling.
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The effectiveness of collaborative medicine reviews in delaying time to next hospitalization for patients with heart failure in the practice setting: results of a cohort study.
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Comparative effects of carvedilol vs bisoprolol for severe congestive heart failure.
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BACKGROUND: Although carvedilol and bisoprolol are effective medicines for the treatment of patients with heart failure (HF), only a few reports have compared their effects. This study was designed to compare the effects of them in patients with severe HF. METHODS AND RESULTS: A total of 655 consecutive patients with HF, categorized as New York Heart Association Class 3 or 4, were retrospectively investigated. Of these patients, 217 were administered beta-blockers after admission and were divided into 2 groups (carvedilol, n=110; bisoprolol, n=107). No significant differences were observed in their characteristics between the 2 groups prior to the introduction of the beta-blockers. After 18 months of follow-up, there were no significant differences in the survival and cardiac event-free rates between the 2 groups. In contrast, there were several significant differences in patients with atrial fibrillation (AF) (carvedilol, n=40; bisoprolol, n=43). The percent changes in heart rate and brain natriuretic peptide level improved significantly in the bisoprolol group than in the carvedilol group. Furthermore, more patients in the bisoprolol group were defibrillated from AF to sinus rhythm than those in the carvedilol group (48% vs 16%; P=0.03). CONCLUSIONS: Our data suggest that the 2 beta-blockers are equally effective in the improvement of severe HF, but bisoprolol shows favorable effects in patients with AF. (+info)
Differential effects of beta-adrenoreceptor antagonists on central and peripheral blood pressure at rest and during exercise.
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