Which medications can serve as antidotes for calcium channel blocker toxicity?

• A. Calcium, glucagon, insulin
• B. Aspirin, naloxone, sodium bicarbonate
• C. Glucose, epinephrine, dopamine
• D. Atropine, nitroglycerin, morphine

Answer: (A)

The correct answer includes calcium, glucagon, and insulin as antidotes for calcium channel blocker toxicity due to their pharmacological actions that can counteract the effects of calcium channel blockers.

Calcium is directly relevant because calcium channel blockers function by inhibiting the influx of calcium ions into cells, which affects myocardial contractility and vascular smooth muscle tone. Administering calcium can help restore the balance by facilitating calcium influx and promoting cardiac cell function, thus counteracting the blocking effects.

Glucagon is effective because it stimulates adenylate cyclase, resulting in increased cAMP levels, which can lead to increased heart rate and contractility, effectively addressing the bradycardia and decreased myocardial contractility associated with calcium channel blocker overdose.

Insulin is also utilized in the management of calcium channel blocker toxicity, particularly to address potential metabolic derangements and promote glucose uptake by the myocardium. By enhancing glucose metabolism, it can improve cardiac function and energy utilization in the event of toxicity.

These three agents work synergistically to mitigate the cardiovascular effects of calcium channel blockers, making them the appropriate antidotes in cases of toxicity.