Renal dialysis patient in cardiac arrest or bradycardia.
Calcium Channel Blocker OD
Hydrofluoric Acid exposure with tetany OR cardiac arrest. 
Tetany may present as: overactive neurological reflexes, spasms of the hands and feet, cramps, and laryngospasm.  
Prophylactically, after exposure to Hydrofluoric Acid

ADULT:  
Cardiac Arrest, CCB OD and Hydrofluoric Acid exposure with tetany or cardiac arrest: 1 g (10 ml) IV
Hydrofluoric Acid Exposure Prophylaxis: 400 mg IV (4 ml)

PEDI: 
Cardiac Arrest & OD: 20 mg/kg IV (max dose 500 mg in Calcium Channel Blocker OD)

THERAPEUTIC ACTION:
Antagonizes cardiac toxicity in hyperkalemia associated with dialysis patients. Reverses symptoms of Calcium Channel Blocker