Calcium channel blocker toxicity: Difference between revisions
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****Note: with higher doses peripheral selectivity is lost | ****Note: with higher doses peripheral selectivity is lost | ||
*****I.e. may see decreased inotrophy, bradycardia | *****I.e. may see decreased inotrophy, bradycardia | ||
** 2. Non-dihydropyridines ( | ** 2. Non-dihydropyridines (verapamil, diltiazem) | ||
*** Stronger effect on heart, weak vasodilators | *** Stronger effect on heart, weak vasodilators | ||
*** Toxicity = Bradycardia, decreased inotropy | *** Toxicity = Bradycardia, decreased inotropy | ||
| Line 52: | Line 52: | ||
===Phase 1=== | ===Phase 1=== | ||
#Charcoal 1g/kg (max 50g) | #Charcoal 1g/kg (max 50g) | ||
##Consider if present | ##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 | #Fluids | ||
#Atropine | #Atropine | ||
##Adult: 0.5-1mg IV q2-3min to max of 3g | ##Adult: 0.5-1mg IV q2-3min to max of 3g | ||
##Ped: 0.02mg/kg (minimum is 0.1mg) | ##Ped: 0.02mg/kg (minimum is 0.1mg) | ||
===Phase 2=== | ===Phase 2=== | ||
#High-dose insulin and glucose | #High-dose insulin and glucose | ||
##Takes 30-60min for effect | ##Takes 30-60min for effect | ||
| Line 75: | Line 71: | ||
##Potassium | ##Potassium | ||
###If <3 administer 20mEq IV | ###If <3 administer 20mEq IV | ||
#Glucagon | |||
##5mg IV bolus q10min x 2 | |||
#Vasopressors | |||
##Norepinephrine is agent of choice | |||
==Disposition== | ==Disposition== | ||
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*Admit all sustained-release ingestions | *Admit all sustained-release ingestions | ||
*D/C if asymptomatic x 6-8hrs | *D/C if asymptomatic x 6-8hrs | ||
==Source== | ==Source== | ||
Revision as of 00:13, 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
- Note: with higher doses peripheral selectivity is lost
- 2. Non-dihydropyridines (verapamil, diltiazem)
- Stronger effect on heart, weak vasodilators
- Toxicity = Bradycardia, decreased inotropy
- 1. Dihydropyridines (nifedipine, amlodipine, nicardipine)
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
- ECG
- PR prolongation
- Bradydysrhythmia
- Glucose
- Chemistry
DDx
- Beta blockers
- More likely to cause CNS changes
- Hypoglycemia is more common
- Digoxin
- Nausea/vomiting is more common
- Clonidine
- Miosis, somnolence
- Cholinergic agents
- SLUDGE
Treatment
Monotherapy only successful for trivial overdoses
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
- Takes 30-60min for effect
- Glucose:
- Adult: 50mL of D50W
- Ped: 2.5mL/kg of D10
- Insulin bolus 1 Unit/kg followed by 0.5units/kg/hr
- Titrate infusion until hypotension is corrected or max 2u/kg/hr
- Potassium
- If <3 administer 20mEq IV
- Glucagon
- 5mg IV bolus q10min x 2
- Vasopressors
- 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