Despite the caveat that hypercalcemia may potentiate the cardiotoxicity of digitalis, calcium infusion is recommended to stabilize the cardiac membrane. In such a situation, calcium should be given slowly. Calcium gluconate is preferred over calcium chloride, as chloride formulation contains three times higher elemental calcium than gluconate version.
Calcium should be given as 10 mL of 10% Ca-gluconate in 100 mL of D-5 water over a period of half an hour. This prevents acute hypercalcemia and minimizes the cardiotoxic effect of "dig."
Said that digoxin-specific antibody fragments is the ideal treatment for symptomatic toxicity.
References:1. Levine M, Nikkanen H, Pallin DJ. The effects of intravenous calcium in patients with digoxin toxicity. J Emerg Med. 2011 Jan;40(1):41-6. doi: 10.1016/j.jemermed.2008.09.027. Epub 2009 Feb 6. PMID: 19201134.