In calcium channel blocker overdose, what calcium salt can be used as an alternative to calcium gluconate?

• A. Calcium chloride
• B. Calcium lactate
• C. Calcium carbonate
• D. Calcium citrate

Answer: (A)

In calcium channel blocker overdose, giving calcium helps overcome the blockade by increasing extracellular calcium, which improves myocardial contractility and conduction despite the blocked channels. Among IV calcium salts, calcium chloride can be used as an alternative to calcium gluconate because it delivers more elemental calcium per amount and has a faster onset, making it more potent for rapidly reversing the toxic effects. Because it is more caustic to veins, it’s usually infused through a central line or a large peripheral vein with careful monitoring.

The other salts listed are not typical IV choices for quick reversal in this setting: calcium lactate, calcium carbonate, and calcium citrate are either less suitable for rapid IV use or are primarily oral supplements with slower bioavailability, so they don’t serve as effective acute alternatives to calcium gluconate.