Beta-Blocker Poisoning

Basics

Description

Other

Normal Physiology

  • Cardiovascular: β1-receptors:
    • ATP converted to cAMP by adenyl cyclase with stimulation of β-receptors
    • cAMP activates protein kinase, which phosphorylates proteins of the sarcoplasmic reticulum
    • Sarcoplasmic reticulum releases calcium
    • Excitation–contraction coupling occurs
  • Effects of β-blockers:
    • Cardiovascular:
      • Decreased excitation/contraction, lowering heart rate and contractility
    • Sodium channel blockade can cause a prolongation of the QRS complex (propranolol, carvedilol)
    • Prolongation of QTc interval leading to ventricular dysrhythmias or Torsades de Pointes (sotalol)
    • Neurologic:
      • CNS effects with the lipophilic agents (propranolol)

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