Beta Blocker Overdose


Beta Blocker Overdose, Beta Blocker Toxicity

  • Pathophysiology
  1. Beta Blocker Overdose is treated the same as Calcium Channel Blocker Overdose
  2. Selective Beta Blockers lose selectivity in Overdose
    1. Overdosed Beta Blockers affect all receptors regardless of whether agent is beta-1 or beta-2 selective
  3. Mechanism
    1. Inhibits fast Sodium channels with decreased contractility and Hypotension, in addition to Bradycardia
    2. Beta-2 blockade results in bronchoconstriction and Hypoglycemia
  • Precautions
  1. Beta Blocker Overdoses are high risk of death (on par with Tricyclic Antidepressants and Calcium Channel Blockers)
    1. Treat at similar intensity as a full code as these patients decompensate rapidly
  • Findings
  • Symptoms and Signs
  1. Primary toxic effects
    1. Bradycardia
    2. Hypotension
  2. Other effects
    1. Acidosis
    2. Bronchospasm
    3. Coma
    4. Hypoglycemia (esp. in children)
      1. Contrast with Hyperglycemia in Calcium Channel Blocker Overdose
    5. Hyperkalemia
    6. Respiratory depression
  3. Lipophilic Beta Blockers (primarily Propranolol, but also Metoprolol and Pindolol)
    1. Seizures
    2. QRS Widening
  • Management
  1. See Calcium Channel Blocker Overdose for management
  2. Expect a rapid decompensation after ingestion (2 hours)
  3. Specific concerns with Beta Blocker Overdose (contrast with Calcium channel Overdose)
    1. Glucagon
      1. Appears more effective in Beta Blocker Overdose than in Calcium Channel Blocker Overdose
      2. See Calcium Channel Blocker Overdose for dosing, mechanism and protocols
    2. Hypoglycemia
      1. Inhibited Beta-2 Adrenergic Receptors (Gluconeogenesis, Glycolysis inhibited by blockade)
      2. Monitor Glucose every 30 min (more often if on euglycemic Insulin protocol)
      3. Start D10 if Glucose is trending downward