The UK Medicines and Healthcare products Regulatory Authority (MHRA) is warning of the potential risk of underdosing with calcium gluconate in patients with severe hyperkalaemia. The MHRA recently authorised the use of calcium gluconate for the treatment of myocardial excitability in acute severe hyperkalaemia and in cardiac resuscitation due to severe hyperkalaemia. Calcium gluconate should be used only in cases of documented severe hyperkalaemia, and should not be routinely administered during cardiac arrest. …