Calcium channel blocker toxicity: Difference between revisions
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==Background== | ==Background== | ||
* Hemodialysis is ineffective | *Hemodialysis is ineffective | ||
* Precipitous deterioration is common (esp w/ verapamil) | *Precipitous deterioration is common (esp w/ verapamil) | ||
*Nifedipine can kill a child with a single pill | |||
*2 Classes: | *2 Classes: | ||
** 1. Dihydropyridines (nifedipine, amlodipine, nicardipine) | ** 1. Dihydropyridines (nifedipine, amlodipine, nicardipine) | ||
| Line 47: | Line 48: | ||
==Treatment== | ==Treatment== | ||
*Monotherapy only successful for trivial overdoses | |||
Phase 1 | |||
*Charcoal 1g/kg (max 50g) | *Charcoal 1g/kg (max 50g) | ||
**Consider if present within 1-2hr with delayed-release preparation | **Consider if present within 1-2hr with delayed-release preparation | ||
*Fluids | |||
*Atropine | |||
**Adult: 0.5-1mg IV q2-3min to max of 3g | |||
**Ped: 0.02mg/kg (minimum is 0.1mg) | |||
*Calcium | |||
**Calcium gluconate 30-60mL of 10% soln | |||
**Calcium chloride 10-20mL of 10% soln (requires central line) | |||
Phase 2 | |||
* | *Glucagon | ||
**5mg IV bolus q10min x 2 | |||
*Vasopressors | |||
**Norepinephrine is agent of choice | |||
*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 | |||
*5mg IV bolus q10min x 2 | ***If <3 administer 20mEq IV | ||
Vasopressors | |||
*Norepinephrine is agent of choice | |||
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 | |||
==Disposition== | ==Disposition== | ||
Revision as of 20:21, 23 March 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 within 1-2hr with delayed-release preparation
- Fluids
- Atropine
- Adult: 0.5-1mg IV q2-3min to max of 3g
- Ped: 0.02mg/kg (minimum is 0.1mg)
- Calcium
- Calcium gluconate 30-60mL of 10% soln
- Calcium chloride 10-20mL of 10% soln (requires central line)
Phase 2
- Glucagon
- 5mg IV bolus q10min x 2
- Vasopressors
- Norepinephrine is agent of choice
- 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
Disposition
- Admit all symptomatic pts
- Admit all sustained-release ingestions
- D/C if asymptomatic x 6-8hrs
See Also
Source
Rosen's