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Patient handout

Calcium channel blocker overdose

PRODUCTION

1. Your condition

This handout is for calcium channel blocker overdose. Your care team identified this based on: reported / suspected verapamil, diltiazem, amlodipine, nifedipine ingestion (acmt 2017).

Other reasons your team may use this plan: bradycardia + hypotension in a patient on or with access to a ccb (crit care 2023); hyperglycemia + shock without diabetic ketoacidosis — ccb until proven otherwise (st-onge crit care med 2017); undifferentiated cardiogenic / vasodilatory shock with toxicologic history (aact/acmt).

2. Your medications

Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.

MedicationStarting doseHowWhenWhat it does
calcium gluconate30–60 mL of 10% (3–6 g) IV over 5–10 min; repeat q10–20 min ×3–4 PRN, then infusion 0.6–1.5 mL/kg/h of 10% titrated to ionized calcium / hemodynamicsIVbolus then continuous infusionACMT 2017 — first antidote; overcomes channel blockade by raising extracellular calcium gradient. Gluconate preferred when only peripheral access (less caustic on extravasation). Target ionized Ca up to ~2× normal; surveil for hypercalcemia (Crit Care 2023)
calcium chloride10–20 mL of 10% (1–2 g) IV via CENTRAL line over 5–10 min; repeat q10–20 min PRN then infusionIV (central)bolus then continuous infusion3× elemental calcium per mL vs gluconate — preferred in severe shock when central access exists; vesicant, central line mandatory (ACMT 2017)
whole-bowel irrigation (polyethylene glycol)PEG-ELS 1–2 L/h (adult) / 25 mL/kg/h (peds) NG until rectal effluent clearPO/NGcontinuous until effluent clearACMT 2017 — SR verapamil/diltiazem form pharmacobezoars; WBI limits ongoing absorption. Activated charcoal 1 g/kg if early and airway protected. Hold if ileus / unprotected airway (Crit Care 2023)

Plan: CCB overdose — antidotal ladder (calcium → HIET core inotrope → vasopressor → lipid / methylene blue → mechanical support)

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

  • Sustained-/extended-release verapamil, diltiazem, or amlodipine ingestion (even if currently asymptomatic) (ACMT 2017)
  • Symptomatic bradycardia / high-grade or complete AV block unresponsive to atropine + calcium boluses (non-DHP phenotype) (Crit Care 2023)(life-threatening)
  • Hypotension / cardiogenic shock not corrected by calcium boluses + IV fluids (St-Onge Crit Care Med 2017)(life-threatening)
  • Hyperglycemia + shock without DKA — pivots diagnosis to CCB (insulin-secretion blockade) vs beta-blocker (St-Onge Crit Care Med 2017)
  • Peri-arrest / shock refractory to calcium + max HIET + ≥2 vasopressors ± lipid/methylene blue (ELSO)(life-threatening)
  • Pediatric ingestion — a single SR verapamil/diltiazem tablet can be lethal in a toddler (Crit Care 2023)(life-threatening)

5. Follow-up

Wean HIET (taper as glucose tolerance falls — risk of hypoglycemia on abrupt stop), de-escalate vasopressors/calcium; psychiatry + safety planning if intentional; medication-safety / lethal-means counselling; pediatric poison-prevention education and Poison Control reporting (AACT/ACMT)

6. Sources

Guideline: ACMT 2017 Position Statement: Interim Guidance for the Use of High-Dose Insulin and Lipid Emulsion in CCB/BB Poisoning + St-Onge et al. Crit Care Med 2017 (Experts Consensus / systematic review on CCB-poisoning management) + AACT/ACMT Lipid Emulsion Workgroup + 2023 Critical Care narrative review of CCB/BB toxicity + ELSO ECPR guidance

  1. pubmed.ncbi.nlm.nih.gov/27749343
  2. pubmed.ncbi.nlm.nih.gov/28169558
  3. pubmed.ncbi.nlm.nih.gov/26059743