Calcium channel blocker toxicity: Difference between revisions

No edit summary
Line 48: Line 48:


==Treatment==
==Treatment==
Monotherapy only successful for trivial overdoses
*Monotherapy only successful for trivial overdoses
*Charcoal 1g/kg (max 50g)
**Consider if present w/in 1-2hr w/ delayed-release preparation


===Phase 1===
#Charcoal 1g/kg (max 50g)
##Consider if present w/in 1-2hr w/ delayed-release preparation
#Calcium
##Calcium gluconate 30-60mL of 10% soln
##Calcium chloride 10-20mL of 10% soln (requires large IV/central line)
#Fluids
#Atropine
##Adult: 0.5-1mg IV q2-3min to max of 3g
##Ped: 0.02mg/kg (minimum is 0.1mg)
===Phase 2===
#High-dose insulin and glucose
#High-dose insulin and glucose
##Takes 30-60min for effect
##Takes 30-60min for effect
Line 67: Line 57:
###Adult: 50mL of D50W
###Adult: 50mL of D50W
###Ped: 2.5mL/kg of D10
###Ped: 2.5mL/kg of D10
##Insulin bolus 1 Unit/kg followed by 0.5units/kg/hr
##Insulin bolus 1 unit/kg followed by 0.5units/kg/hr
###Titrate infusion until hypotension is corrected or max 2u/kg/hr
###Titrate infusion until hypotension is corrected or max 2u/kg/hr
##Potassium
##Potassium
###If <3 administer 20mEq IV
###If <3 administer 20mEq IV
#Calcium
##Calcium gluconate 30-60mL of 10% soln
##Calcium chloride 10-20mL of 10% soln (requires large IV/central line)
#Fluids
#Atropine
##Adult: 0.5-1mg IV q2-3min to max of 3g
##Ped: 0.02mg/kg (minimum is 0.1mg)
#Glucagon
#Glucagon
##5mg IV bolus q10min x 2
##5mg IV bolus q10min x 2

Revision as of 00:19, 15 June 2011

Background

  • Hemodialysis is ineffective
  • Precipitous deterioration is common (esp w/ verapamil)
  • Nifedipine can kill a child with a single pill
  • 2 Classes:
    • 1. Dihydropyridines (nifedipine, amlodipine, nicardipine)
      • Systemic vasodilation, mild effect on heart
      • Toxicity = Hypotension, reflex tachycardia
        • Note: with higher doses peripheral selectivity is lost
          • I.e. may see decreased inotrophy, bradycardia
    • 2. Non-dihydropyridines (verapamil, diltiazem)
      • Stronger effect on heart, weak vasodilators
      • Toxicity = Bradycardia, decreased inotropy

Diagnosis

  • Cardiovascular
    • Hypotension (any CCB overdose)
    • Bradycardia (usually only seen with verapamil/dilt)
    • AV/sinus block
    • CHF
  • Pulmonary
    • Respiratory depression
    • Pulmonary edema
  • GI
    • Nausea/vomiting
  • Neurologic
    • Lethargy, confusion, coma
  • Metabolic
    • Hyperglycemia

Work-Up

  1. ECG
    1. PR prolongation
    2. Bradydysrhythmia
  2. Glucose
  3. Chemistry

DDx

  1. Beta blockers
    1. More likely to cause CNS changes
    2. Hypoglycemia is more common
  2. Digoxin
    1. Nausea/vomiting is more common
  3. Clonidine
    1. Miosis, somnolence
  4. Cholinergic agents
    1. SLUDGE

Treatment

  • Monotherapy only successful for trivial overdoses
  • Charcoal 1g/kg (max 50g)
    • Consider if present w/in 1-2hr w/ delayed-release preparation
  1. High-dose insulin and glucose
    1. Takes 30-60min for effect
    2. Glucose:
      1. Adult: 50mL of D50W
      2. Ped: 2.5mL/kg of D10
    3. Insulin bolus 1 unit/kg followed by 0.5units/kg/hr
      1. Titrate infusion until hypotension is corrected or max 2u/kg/hr
    4. Potassium
      1. If <3 administer 20mEq IV
  2. Calcium
    1. Calcium gluconate 30-60mL of 10% soln
    2. Calcium chloride 10-20mL of 10% soln (requires large IV/central line)
  3. Fluids
  4. Atropine
    1. Adult: 0.5-1mg IV q2-3min to max of 3g
    2. Ped: 0.02mg/kg (minimum is 0.1mg)
  5. Glucagon
    1. 5mg IV bolus q10min x 2
  6. Vasopressors
    1. Norepinephrine is agent of choice

Disposition

  • Admit all symptomatic pts
  • Admit all sustained-release ingestions
  • D/C if asymptomatic x 6-8hrs

Source

Rosen's

Retrieved from "https://www.wikem.org/w/index.php?title=Calcium_channel_blocker_toxicity&oldid=2930"