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Beta Blocker
Aka: Beta Blocker, Beta-Blocker, Beta Adrenergic Antagonist, Beta Adrenoceptor Blocking Drug, Atenolol, Timolol, Nadolol
- See Also
- Carvedilol
- Esmolol
- Metoprolol
- Propranolol
- Beta Blocker Overdose
- Perioperative Beta Blocker
- History: Sir James Black and Propranolol
- Sir James Black won 1988 Nobel Prize for Propranolol
- Synthesized Propranolol first in the 1960's
- Revolutionized cardiovascular medicine
- Indications
- Hypertension
- Atrial Fibrillation Rate Control
- Coronary Artery Disease without prior Myocardial Infarction
- Consider to reduce Anginal symptoms and improve Exercise tolerance
- Myocardial Infarction without Congestive Heart Failure
- Continue for at least 2-3 years after Myocardial Infarction
- Stable Congestive Heart Failure (Carvedilol, Metoprolol, Bisoprolol)
- Continue Beta Blocker indefinately
- Arrhythmia refractory to other modality
- Recurrent Ventricular Tachycardia
- Recurrent Ventricular Fibrillation
- Migraine Prophylaxis
- Contraindications
- Reactive Airway Disease and Obstructive Lung Disease (Asthma, COPD)
- Cardioselective Beta Blockers (e.g. Metoprolol) are not contraindicated
- Avoid non-selective Beta Blockers (Carvedilol, Propranolol)
- See Bronchospasm under adverse effects below
- Acute Congestive Heart Failure exascerbation
- Concurrent Calcium Channel Blocker use
- Precautions
- Abrupt discontinuation is associated with exacerbation of Angina and risk of MI (FDA black box warning)
- Taper over one to two weeks
- Mechanism: General
- Beta Adrenergic Receptor Antagonist
- Inhibits effects of circulating Catecholamines
- Blocks Beta Adrenergic Receptors
- Beta-1 Adrenergic Receptors
- Cardiac muscle (primarily contraction)
- Allow Calcium entry into cells (cAMP mediated)
- Inotropic and chronotropic effects
- Beta-2 Adrenergic Receptors
- Smooth muscle and Bronchioles
- Beta-3 Adrenergic Receptors
- Lipolysis
- Mechanism: Cardiovascular Specific (Beta-1 Adrenergic Receptor blockade)
- General Cardiac Effects
- Negative Inotrope
- Reduces Myocardial Contractility
- Negative Chronotrope
- Reduces Heart Rate
- Reduces Blood Pressure
- Reduces Myocardial Oxygen Demand
- Antiarrhythmic effects
- Seen with non-selective Beta Blockers (Propranolol)
- Controls Catecholamine stimulated Arrhythmias
- Recurrent Ventricular Tachycardia
- Recurrent Ventricular Fibrillation
- Controls Myocardial Ischemia related Arrhythmias
- Reduces AV Nodal Conduction
- Slows ventricular response
- Atrial Fibrillation
- Atrial Flutter
- Paroxysmal Supraventricular Tachycardia
- Quinidine-like effect on action potential
- Seen with Propranolol
- Myocardial protection
- Reduces Myocardial Infarction size
- Prevents re-infarction after Thrombolytic
- Mechanism: Non-Selective effects (non-cardiovascular effects)
- Beta 2 Adrenergic Receptor blockade
- Results in bronchoconstriction
- Beta 2 Adrenergic Receptors affect Bronchiole and smooth muscles
- Non-Selective Beta Blockers (e.g. Propranolol)
- Selective Beta Blockers lose selectivity at high dose and in Overdose
- High dose Metoprolol (over 200 mg/day)
- High dose Esmolol (over 300 ug/kg/min)
- Beta 3 Adrenergic Receptor blockade
- Lipolysis inhibited
- Adverse Effects
- SA and AV nodal blockade
- Avoid in over age 75 unless secondary indication
- Do not use with Calcium Channel Blockers
- Hypotension or Orthostasis
- Congestive Heart Failure
- Treat with vasodilators and Diuretics with inotropes
- Bradycardia
- Treat with Atropine, Transcutaneous pacing, Dopamine
- Bronchospasm
- Treat with Sympathomimetics and Aminophylline
- Unlikely to occur in cardioselective Beta Blockers at standard doses
- Study looked at Atenolol, Metoprolol, bisoprolol
- First dose may lower FEV1 (responds to Albuterol)
- Continuous use does not impair lung function
- Salpeter (2002) Ann Intern Med 137:715-25 [PubMed]
- Major Depression exacerbation
- Fatigue
-
Drug Interactions: Decreased Heart Rate and AV Conduction
- Amiodarone
- Diltiazem
- Verapamil
- Propafenone (Rythmol)
- Sotalol (Betapace)
- Preparations: Cardioselective (Beta-1 Selective Adrenergic Blockade)
- Atenolol (Tenormin)
- Despite daily dosing, duration of activity is not a a full 24 hours
- Consider dividing dosing into twice daily (e.g. 50 mg twice daily)
- Not as effective as other Beta Blockers in cardiovascular disease prevention (especially with Hypertension present)
- Consider Metoprolol, Bisoprolol, Carvedilol or Nadolol instead
- Carlberg (2004) Lancet 364:1684-9 [PubMed]
- Dosing
- Regular: 50 mg PO daily (MAX: 100 mg/day)
- IV (Acute MI): 5 mg IV over 5 min, repeat in 10 min
- Bisoprolol
- Most cardioselective of Beta Blockers
- Metoprolol (Lopressor, Toprol XL)
- Preferred Beta Blocker for Hypertension, Myocardial Infarction, Atrial Fibrillation Rate Control
- Metoprolol Succinate (Toprol XL) is preferred over Metoprolol Tartrate (Lopressor)
- Esmolol Hydrochloride (Brevibloc)
- Intravenous very short acting Beta Blocker used in Emergent Hypertension Management
- Nebivolol (Bystolic)
- Third generation Beta Blocker with vasodilatory properties (nitric oxide release)
- Other cardioselective Beta Blockers
- Betaxolol
- Acebutolol
- Preparations: Nonselective (Beta-1 and Beta-2 Adrenergic Blockade)
- Timolol (Blocadren)
- Dose: 10 mg PO bid (MAX 60 mg/day)
- Nadolol (Corgard)
- Dose: 40 mg PO qd (MAX 320 mg/day)
- Propranolol (Inderal)
- Used for Essential Tremor, symptomatic Hyperthyroidism, Migraine Prophylaxis, symptomatic Palpitations
- Timolol
- Typically used topically for Open Angle Glaucoma
- Sotalol
- Primarily used as Antiarrhythmic
- Other non-selective Beta Blockers
- Carteolol
- Oxprenolol
- Penbutolol
- Preparations: Combined Alpha-1, Beta-1 and Beta-2 Adrenergic Blockade
- Labetalol
- Used in Hypertension in Pregnancy, Resistant Hypertension, CVA Blood Pressure Control
- Carvedilol (Coreg)
- Third generation Beta Blocker with vasodilatory properties (alpha blocker)
- Used in Congestive Heart Failure
- References
- (2012) Presc Lett 19(12): 67-8
- Yen (2015) Crit Dec Emerg Med 29(10): 18-23