Beta Adrenergic Receptor Antagonist

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Contents 1 More Specific Terms 2 Introduction 3 Indications 4 Contraindications 5 Adverse-effects 6 Drug-interactions 7 Mechanism-of-action 8 More General Terms 9 Additional Terms 10 References

More Specific Terms

• beta-1 adrenergic receptor antagonist (beta-1 blocker)
• non-specific beta-adrenergic receptor antagonist (non-specific beta-blocker)

Introduction

• A molecule/drug that blocks the effect of catecholamines on beta adrenergic receptors, producing a decrease in heart rate & oxygen demand in the myocardium.

Indications

• myocardial infarction*
• states of catecholamine excess

• thyrotoxicosis
• pheochromocytoma
• may leave alpha adrenergic effects unopposed

• supraventricular tachycardia

• atrial fibrillation
• atrial flutter
• sinus tachycardia

• congenital long QT syndrome (may prevent episodes of torsades de pointes)
• neurocardiogenic syncope
• hypertension#
• treatment of heart failure

• * no advantage of beta-blockers for preventing myocardial infarction or death when used to treat hypertension [9]
• # not 1st line for uncomplicated hypertension [12]

Contraindications

• asthma
• symptomatic bradycardia
• uncontrolled or unstable heart failure
• severe peripheral vascular disease
• Raynaud's phenomenon
• pheochromocytoma

• Caution:

• when discontinuing beta blocker, taper over 1-2 weeks
• intermittent claudication
• may mask signs & symptoms of hypoglycemia
• use with caution in patients at risk for anaphylaxis

• may inhibit effects or epinephrine & make anaphylaxis more severe & difficult to treat [7]

Adverse-effects

• bronchospasm
• bradycardia
• decreased cardiac output
• negative inotropic effects
• abrupt withdrawal may precipitate arrhythmia or angina
• may mask symptoms of hypoglycemia
• unopposed alpha adrenergic activity may potentiate coronary artery vasospasm
• lethargy
• confusion & diminished ability to concentrate
• impotence
• potentiation of Raynaud's phenomenon
• nightmares
• insomnia
• depression is [2], but is not [1], & might be [3] an adverse effect of beta-blockers
• may diminish effect of sulfonylureas
• hyperkalemia (extracellular shift of K+)
• metabolic alkalosis
• increased triglycerides
• diminished HDL cholesterol
• may exacerbate psoriasis [4]
• may increase risk of developing diabetes mellitus [5]
• increased cardiovascular mortality directly correlates with magnitude of heart rate slowing when used to treat hypertension [12]
  

• Overdose:

• supportive therapy:

• IV access
• continuous cardiac monitoring

• bradycardia

• atropine generally not useful (not vagally mediated)
• glucagon 2-4 mg IV over 1-2 minutes, then start infusion at 2-5 mg/ hr (do not exceed 10 mg/ hr);

• may cause nausea/vomiting
• monitor for vagally-mediated bradycardia

• ventricular pacing

• hypotension

• calcium gluconate 3-9 g IV through peripheral line
• calcium chloride 1-2 g IV over 10 minutes through a central venous catheter is alternative (caution: sclerosing agent)
• high-dose insulin euglycemia therapy
• intra-aortic balloon pump
  

• drug adverse effects of beta-adrenergic receptor antagonists

Drug-interactions

• alpha-1 adrenergic antagonists: orthostatic hypotension
• amiodarone: symptomatic bradycardia & sinus arrest
• sympathomimetics
• lidocaine serum levels may increase by 20-30%
• methacholine
• methyldopa ( paradoxical hypertensive response to stress)
• NSAIDs may interfere with antihypertensive effect
  
• drug interaction(s) of beta-2 adrenergic receptor agonists with beta adrenergic receptor antagonists
• drug interaction(s) of beta-adrenergic receptor antagonists with thyroid hormone
• drug interaction(s) of beta-adrenergic receptor antagonists with sulfinpyrazone
• drug interaction(s) of beta-adrenergic receptor antagonists with salicylate
• drug interaction(s) of beta-adrenergic receptor antagonists with rifampin
• drug interaction(s) of beta-adrenergic receptor antagonists with ampicillin
• drug interaction(s) of beta-adrenergic receptor antagonists with colestipol
• drug interaction(s) of beta-adrenergic receptor antagonists with cholestyramine
• drug interaction(s) of beta-adrenergic receptor antagonists with barbiturates
• drug interaction(s) of beta-adrenergic receptor antagonists with calcium salts
• drug interaction(s) of beta-adrenergic receptor antagonists with aluminum carbonate
• drug interaction(s) of beta-adrenergic receptor antagonists with aluminum hydroxide
• drug interaction(s) of beta-adrenergic receptor antagonists with prazosin
• drug interaction(s) of beta-adrenergic receptor antagonists with lidocaine
• drug interaction(s) of beta-adrenergic receptor antagonists with ergot alkaloids
• drug interaction(s) of beta-adrenergic receptor antagonists with clonidine
• drug interaction(s) of beta-adrenergic receptor antagonists with benzodiazepines
• drug interaction(s) of beta-adrenergic receptor antagonists with benzodiazepines
• drug interaction(s) of beta-adrenergic receptor antagonists with quinolones
• drug interaction(s) of beta-adrenergic receptor antagonists with quinidine
• drug interaction(s) of beta-adrenergic receptor antagonists with propafenone
• drug interaction(s) of beta-adrenergic receptor antagonists with phenothiazines
• drug interaction(s) of beta-adrenergic receptor antagonists with MAO inhibitors
• drug interaction(s) of beta-adrenergic receptor antagonists with loop diuretics
• drug interaction(s) of beta-adrenergic receptor antagonists with hydralazine
• drug interaction(s) of beta-adrenergic receptor antagonists with histamine H2 receptor antagonists
• drug interaction(s) of beta-adrenergic receptor antagonists with haloperidol
• drug interaction(s) of beta-adrenergic receptor antagonists with flecainide
• drug interaction(s) of beta-adrenergic receptor antagonists with oral contraceptives
• drug interaction(s) of beta-adrenergic receptor antagonists with calcium channel blockers
• drug interaction(s) of beta-adrenergic receptor antagonists with sulfonylureas
• drug interaction(s) of beta blockers with ACE inhibitors
• drug interaction(s) of spironolactone with beta blockers
• drug interaction(s) of NSAIDs with beta blockers
• drug interaction(s) of ACE inhibitors, angiotensin II receptor antagonists & beta-blockers

Mechanism-of-action

• antagonism at beta-adrenergic receptor

• some are specific for the beta-1 adrenergic receptor
• beta-adrenergic receptor blockade leaves unbalanced alpha-adrenergic receptor activity (which tends to increase with age)

• polymorphism in the ADRB2 gene (C & G) alleles associated with different mortality when treated with beta-blocker after acute coronary syndrome

More General Terms

• adrenergic receptor antagonist

Additional Terms

• beta adrenergic receptor

References

1. Medical Knowledge Self Assessment Program (MKSAP) 11, 15 American College of Physicians, Philadelphia 1998
2. Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 158-59
3. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 474-75, 491
4. The Washington Manual of Medical Therapeutics, 33rd edition Foster C et al (eds) Lippincott, Williams & Wilkins, Philadelphia, 2010, pg 969
5. Journal Watch 20(9): 72, 2000 Gress TW, Nieto FJ, Shahar E, Wofford MR, Brancati FL. Hypertension and antihypertensive therapy as risk factors for type 2 diabetes mellitus. Atherosclerosis Risk in Communities Study. N Engl J Med. 2000 Mar 30;342(13):905-12. PMID: [1]
6. Prescriber's Letter 12(4): 2005 Comparison of Beta-Blockers Detail-Document#: [2] (subscription needed) [3]
7. Prescriber's Letter 12(7): 2005 Should Some Drugs Be Avoided in Patients at Risk of Anaphylaxis? Detail-Document#: [4] (subscription needed) [5]
8. Lanfear DE, Jones PG, Marsh S, Cresci S, McLeod HL, Spertus JA. Beta2-adrenergic receptor genotype and survival among patients receiving beta-blocker therapy after an acute coronary syndrome. JAMA. 2005 Sep 28;294(12):1526-33. PMID: [6]
9. Lindholm LH, Carlberg B, Samuelsson O. Should beta blockers remain first choice in the treatment of primary hypertension? A meta-analysis. Lancet. 2005 Oct 29-Nov 4;366(9496):1545-53. PMID: [7]
   - Beevers DG. The end of beta blockers for uncomplicated hypertension? Lancet. 2005 Oct 29-Nov 4;366(9496):1510-2. No abstract available. PMID: [8]
10. Khan N and McAlister FA, Re-examining the efficacy of beta blockers for treatment of hypertension. A meta-analysis. CMAJ 2006; 174:1737 PMID: [9]
11. Prescriber's Letter 14(8): 2007 CHART: AHA Blood Pressure Goals and Treatments Detail-Document#: [10] (subscription needed) [11]
12. Bangalore S et sl, Relation of beta-blocker-induced heart rate lowering and cardioprotection in hypertension. J Am Coll Cardiol 2008 52:1482 PMID: [12]
    - Kaplan NM Beta-blockers in hypertension: Adding insult to injury. J Am Coll Cardiol 2008 52:1490 PMID: [13]
13. Prescriber's Letter 14(8): 2007 Comparison of Oral Beta-Blockers Detail-Document#: [14] (subscription needed) [15]
14. National Guideline Clearinghouse Expert consensus document on beta-adrenergic receptor blockers. ngc-guideline: [16]

beta adrenergic receptor antagonist (beta-blocker)