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.