[Toxicity of calcium inhibitors]

Calcium antagonists decrease the intracellular concentration of calcium ions. They act essentially on the smooth vascular muscle, on the cardiac muscle and on the automatic and conducting cells in the heart. At toxic doses these effects induce hypotension, shock and disturbances of sinusal automatism and atrio-ventricular conduction. The toxicity of the different calcium antagonists varies according to their tissue specificity. The treatment of overdose includes gastric lavage, oral activated charcoal, cardiorespiratory support, especially alphamimetic vasopressors for shock or hypotension, adrenaline or cardiac pacing for atrio-ventricular block.