Podcast #323: Calcium Channel Toxicity

Author: Jared Scott, M.D.

Educational Pearls:

  • Cardiac myocytes and vascular smooth muscle are dependent on an intracellular calcium influx for contraction. Pancreatic beta cells rely on calcium to release insulin.
  • Calcium channel blockers will decrease cardiac contractility and heart rate, but will also cause vascular smooth muscle relaxation with a subsequent decrease in systemic vascular resistance.
  • Resultant cardiac depression and hypotension.
  • Pancreatic beta cells also use calcium to release insulin, so calcium channel blockade can cause hyperglycemia.
  • Treatment for calcium channel toxicity include: fluid resuscitation, calcium gluconate, vasopressors, and high dose insulin.
  • Dosing for insulin therapy is usually 1-5 Units/kg/hr. Make sure to add dextrose!

 

References:

Boyer EW, Shannon M. (2001).Treatment of calcium-channel-blocker intoxication with insulin infusion. New England Journal of Medicine. 344:1721.

Proano L, Chiang WK, Wang RY. (1995).Calcium channel blocker overdose. American Journal of Emergency Medicine. 13:444.

St-Onge M, Dubé PA, Gosselin S, et al. (2014). Treatment for calcium channel blocker poisoning: a systematic review. Clinical Toxicology. 52:926.

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