Cardiac arrhythmias and circulatory collapse account for the high mortality reported after severe chloroquine poisoning. We have recently observed a 17-year-old man who ingested an 8 g chloroquine overdose. Cardiac arrest occurred within 1 h. Cardiogenic shock was refractory to epinephrine, dopamine and molar sodium lactate. Amrinone, a bipyridine analog, was then successfully used to improve haemodynamic conditions.