• 제목/요약/키워드: blockers

검색결과 303건 처리시간 0.026초

Beta Blockers in Contemporary Cardiology: Is It Better to Cast Them Out?

  • Javaid Ahmad Dar;John Roshan Jacob
    • Korean Circulation Journal
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    • 제54권4호
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    • pp.165-171
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    • 2024
  • Beta blockers are one of the commonest prescription drugs in medicine and they have been thought to revolutionize the treatment of heart failure (HF) with reduced ejection fraction (HFrEF) in the last century. In addition to HFrEF, they are prescribed for a variety of diseases in cardiology from hypertension to HF, angina, and stable coronary artery disease (CAD). The increased prescription of beta blockers in conditions like HF with preserved ejection fraction (HFpEF), and stable CAD may be doing more harm than good as per the data we have so far. The available data shows that beta blockers are associated with increased stroke risk and atrial fibrillation (AF) in hypertension and in patients with HFpEF, they have been associated with decreased exercise capacity. In patients with stable CAD and patients with myocardial infarction with normal systolic functions, beta blockers don't offer any mortality benefit. In this article, we critically review the common indications and the uses of beta blockers in patients with HFpEF, CAD, hypertension and AF and we propose that beta blockers are overprescribed under the shadow of their beneficial effects in patients with HFrEF.

Analytic Formulation of Transmission Light Intensity of Hole Blockers in Intensity-based Polymer Optical Fiber Sensors

  • Kwon, Il-Bum;Kim, Chi-Yeop;Shim, Chan-Wook;Hwang, Du-Sun;Chung, Yung-Joo
    • 센서학회지
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    • 제20권4호
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    • pp.221-225
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    • 2011
  • Intensity-based optical fiber sensors are devised using a blocker which is located between two polymer optical fibers(POFs), one fiber is light-in and the other is light-out. This blocker is moved by an external displacement. Therefore, finding a general formulation of the relation between this displacement and transmission light intensity of various blockers is important to help develop intensity-based optical fiber sensors. In this paper, we consider blockers with arbitrary shapes from circular holes to inclined angled blockers. The transmission light intensities of such blockers should be determined by this generalized equation. In order to verify this equation, the calculated intensities of the blockers are compared with the values acquired from experiment. In the comparison, it is shown that the analytic equation can give the exact values of the transmitted light intensities for the assorted blockers. The range of the displacement measurement is also shown to be about 6 times of the radius of the hole in the case of a 9 degree inclined angle blocker.

Separation of the Enantiomers of β-Blockers Using Brush Type Chiral Stationary Phase Derived from Conformationally Rigid α-Amino β-Lactam

  • Pirkle, William H.;Lee, Won-Jae
    • Bulletin of the Korean Chemical Society
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    • 제31권3호
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    • pp.620-623
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    • 2010
  • A brush type chiral stationary phase (CSP 2) derived from ${\alpha}$-amino ${\beta}$-lactam was prepared for the separation of the enantiomers of ${\beta}$-blockers. Compared to the CSP derived from ${\alpha}$-amino phosphonate (CSP 1), in general, the conformationally rigid CSP 2 showed greater scope and much enhanced enantioselectivity for the resolution of ${\beta}$-blockers. The effect of various salt additives on enantioseparation of ${\beta}$-blockers in the mobile phase was investigated. The unusual effect of temperature on the chromatographic behaviors was observed on CSP 2. It also afforded appreciable increases in enantioselectivity without significantly affecting resolution, as the column temperature was reduced.

Are Beta Blockers New Potential Anticancer Agents?

  • Akbar, Shahid;Alsharidah, Mansour Saleh
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권22호
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    • pp.9567-9574
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    • 2014
  • ${\beta}$-Blockers have been one of the most widely used and versatile drugs for the past half a century. A new potential for their use as anti-cancer drugs has emerged in the past few years. Various retrospective case control studies have been suggestive that use of ${\beta}$-blockers before the diagnosis of cancer could have preventive and protective effects against non-small cell lung carcinoma, melanoma, and breast, pancreatic and prostate cancers. Experimental and clinical observations are still inconclusive with some inconsistent findings. However, indications are pointing toward a positive role of some ${\beta}$-blockers against certain forms of cancers. This mini review is an effort to present the up to date published results of case-control studies and experimental findings.

항 히스타민제의 $H_1$ 수용체와 무스카린 수용체에 대한 상대적 역가 (Relative potency of antihistaminics for $H_1$-and muscarinic receptors)

  • 이신웅;박영주;이정수
    • 약학회지
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    • 제37권4호
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    • pp.397-407
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    • 1993
  • The muscarinic antagonist l-[benzilic-4,4'-$^3H$]quinuclidinyl benzilate([$^3H$]QNB) bound to a single class of muscarinic receptor with high affinity in guinea pig ileal membranes. The $K_{D}$ and B$_{max}$ values for [$^3H$]QNB calculated from analysis of saturation isotherms were 54 pM and 156fmol/mg, respectively. H$_{1}$-blockers inhibited [$^3H$]QNB binding to ileal membranes with $K_{i}$ values ranged from 0.008 $\mu{M}$ to 1.6 $\mu{M}$. The pseudo-Hill coefficients of H$_{1}$-blockers for inhibition of [$^3H$]QNB binding to the ileal membranes were close to unit. The $K_{i}$ values for H$_{1}$-blockers were similar to the $K_{M}$ values calculated by Schild plot of functional data obtained from inhibition of the carbachol-induced contraction in guinea-pig ileum, suggesting that binding of H$_{1}$-blockers vs [$^3H$]QNB in ileal membranes represents an interaction with a receptor of physiological relevance. The $K_{H}$ values of H$_{1}$-blockers for H$_{1}$-receptor estimated from inhibition of the histamine-induced contraction were the range of 0.15 nM to 56.5 nM. The $K_{M}$/K$_{H}$ ratio of H$_{1}$-blockers varied over a wide range of 3 to 2300. Thus, the antihistaminic potencies of H$_{1}$-blockers do not correlate with their antimuscarinic potencies, which suggest that antihistamines have different antimuscarinic potencies in therapeutic blood levels causing similar antiallergic effect. Among 13 traditional antihistaminics examined in this study, drug having the highest and the lowest $K_{M}$/K$_{H}$ ratio is triprolidine and diphenidol, respectively. The present results demonstrate that the antimuscarinic property of antihistamines is not necessary for their antiallergic effect, and data on the affinity of antihistamines for muscarinic and H$_{1}$-receptors can be an important parameter in the selection and evaluation of these drugs.

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The Clinical Impact of β-Blocker Therapy on Patients With Chronic Coronary Artery Disease After Percutaneous Coronary Intervention

  • Jiesuck Park;Jung-Kyu Han;Jeehoon Kang;In-Ho Chae;Sung Yun Lee;Young Jin Choi;Jay Young Rhew;Seung-Woon Rha;Eun-Seok Shin;Seong-Ill Woo;Han Cheol Lee;Kook-Jin Chun;DooIl Kim;Jin-Ok Jeong;Jang-Whan Bae;Han-Mo Yang;Kyung Woo Park;Hyun-Jae Kang;Bon-Kwon Koo;Hyo-Soo Kim
    • Korean Circulation Journal
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    • 제52권7호
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    • pp.544-555
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    • 2022
  • Background and Objectives: The outcome benefits of β-blockers in chronic coronary artery disease (CAD) have not been fully assessed. We evaluated the prognostic impact of β-blockers on patients with chronic CAD after percutaneous coronary intervention (PCI). Methods: A total of 3,075 patients with chronic CAD were included from the Grand Drug-Eluting Stent registry. We analyzed β-blocker prescriptions, including doses and types, in each patient at 3-month intervals from discharge. After propensity score matching, 1,170 pairs of patients (β-blockers vs. no β-blockers) were derived. Primary outcome was defined as a composite endpoint of all-cause death and myocardial infarction (MI). We further analyzed the outcome benefits of different doses (low-, medium-, and high-dose) and types (conventional or vasodilating) of β-blockers. Results: During a median (interquartile range) follow-up of 3.1 (3.0-3.1) years, 134 (5.7%) patients experienced primary outcome. Overall, β-blockers demonstrated no significant benefit in primary outcome (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.63-1.24), all-cause death (HR, 0.87; 95% CI, 0.60-1.25), and MI (HR, 1.25; 95% CI, 0.49-3.15). In subgroup analysis, β-blockers were associated with a lower risk of all-cause death in patients with previous MI and/or revascularization (HR, 0.38; 95% CI, 0.14-0.99) (p for interaction=0.045). No significant associations were found for the clinical outcomes with different doses and types of β-blockers. Conclusions: Overall, β-blocker therapy was not associated with better clinical outcomes in patients with chronic CAD undergoing PCI. Limited mortality benefit of β-blockers may exist for patients with previous MI and/or revascularization.

생체시료로부터 미량 $\beta$-Blockers의 동시고상추출에 사용될 흡착제들의 특성 (Characterization of Adsorbents for the Simultaneous Solid-Phase Extraction of Trace $\beta$-Blockers from Biological Samples)

  • 김경례;김도정
    • 분석과학
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    • 제6권4호
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    • pp.375-381
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    • 1993
  • 생체시료 중 ${\beta}$-blockers의 동시분석을 위한 시료 전처리 과정에서 고상추출법을 사용하기 위해 4가지 흡착제의 흡착 및 탈착 효율을 조사하였다. 용출 용매로서 methanol을 사용하였을 때 Chromosorb 107이 가장 높은 회수율을 보였다. ${\beta}$-Blockers의 breakthrough 조사를 하여 Chromosorb 107 컬럼의 우수한 흡착 및 탈착 성질을 혈청 중 2~8 ppm 농도 범위의 ${\beta}$-blockers를 동시에 고상추출하는 데 Chromosorb 107/methanol의 유용성을 조사하였다.

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Cinnarizine을 Propranolol이나 Metoprolol과 병용할 때의 혈압강하효과(血壓降下效果)에 관한 약리학적(藥理學的) 연구(硏究)(III) -생화학적(生化學的) 변화(變化)에 대한 영향- (Pharmacological Studies on the Antihypertensive Effects of Cinnarizine Coadministered with Propranolol or Metoprolol(III) -Effects on Biochemical Changes-)

  • 허인회;안형수
    • 약학회지
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    • 제28권5호
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    • pp.265-273
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    • 1984
  • The effects of cinnarizine, $Ca^{2+}-antagonist$, on the antihypertensive effect of coadministered ${\beta}-blockers$, propranolol and metoprolol, were investigated in SHR. Drugs were coadministered orally for 4 weeks. Hemodynamic and biochemical changes induced by above drugs were determined to elucidate their mechanism of action. a) Cardiohypertropy of SHR was significantly improved by the treatment of ${\beta}-blockers$ as well as combination with cinnarizine and ${\beta}-blockers$. b) $Mg^{2+}-contents$ were increased in ventricle and decreased in plasma and aorta in all of the groups, especially in the group of propranolol with cinnarizine. c) c-GMP contents in ventricle were increased when cinnarizine was coadministered with propranolol, and c-GMP contents in aorta were increased when cinnarizine was coadministered with metoprolol, camparing with propranolol or metoprolol alone-treated group. d) Plasma renin activity appeared to be increased in cinnarizine treated alone, but reduced by combination with ${\beta}-blockers$. e) Triglycerides and $Na^+$ contents in serum were decreased in the group of metoprolol with cinnarizine, comparing with metoprolol alone-treated group. Increased $K^+\;and\;Ca^{2+}$excretions in urine by ${\beta}-blockers$ were inhibited by cinnarizine, so $Na^+/K^+$ excretion ratios were increased. Diuretic effects was showed in metoprolol alone treated group, but reduced when coadministered with cinnarizine.

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Pharmacophore Modelling, Quantitative Structure Activity Relationship (QSAR) and Docking Studies of Pyrimidine Analogs as Potential Calcium Channel Blockers

  • Choudhari, Prafulla B.;Bhatia, Manish S.;Jadhav, Swapnil D.
    • 대한화학회지
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    • 제57권1호
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    • pp.99-103
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    • 2013
  • The present communication deals with the Pharmacophore modeling, 3D QSAR and docking analysis on series of Pyrimidine derivatives as potential calcium channel blockers. The computational studies showed hydrogen bond donor, hydrogen bond acceptor, and hydrophobic group are important features for calcium channel blocking activity. These studies showed that Pyrimidine scaffold can be utilized for designing of novel calcium channels blockers for CVS disorders.

Chiral separation of $\beta$-blockers after derivatizalion wilh a new chiral derivalizalion agen1.GATC and Comparison wilh GITC on derivalizing conditions and chromalographic paramelers

  • Ko, Mi-Young;Shin, Dae-Hong;Seo, Sang-Hun;Kim, Kyeong-Ho
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.398.1-398.1
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    • 2002
  • A new chiral derivatization agent with sugar moiety. 2, 3.4, 6-tetra-O-acetyl-D-galactopyranosyl isothiocyanate (GATC) was synthesized. Several $\beta$-blockers were investigated for the possible separation of the enantiomers by reversed-phase HPLC after derivatization with this new chiral derivatization agent (GATC). GATC was reacted readily with $\beta$-blockers at room temperature and the reaction mixture could directly be injected into the HPLC system. (omitted)

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