High-dose insulin should be used before vasopressors/inotropes in calcium-channel blocker toxicity.

High-dose insulin (HDI) therapy with adapted glucose supplementation to maintain euglycaemia has been suggested to treat calcium-channel blocker (CCB) poisonings. Its underlying mechanisms of action are now well documented. We present a narrative review of the published experimental studies, case reports and experts' opinions to support the effectiveness and safety of HDI in the treatment of CCB poisoning. Our review strongly encourages the use of HDI as first-line therapy in CCB-poisoned patients in the presence of cardiovascular compromise, especially if cardiac function impairment has been diagnosed, before, but without delaying, the administration of vasopressors/inotropic drugs.