[Successful treatment by 4--aminopyridine of three cases of severe verapamil poisoning].

Three cases of verapamil intoxication were presented. In all cases shock and circulatory insufficiency were observed. In case no. 1 respiratory insufficiency and confusion were observed, in case no. 3 second-degree atrioventricular block was noted. The protracted hypotension (shock), circulatory insufficiency and atrioventricular block did not respond to calcium therapy, high dose of vasopressor amines and atropine. The addition of 4-aminopyridine (4-AP) infusion resulted in fast receding of poisoning symptoms; receding of atrioventricular block, cardiogenic shock and circulatory insufficiency. These cases suggest the usefulness of 4-AP in the treatment of verapamil poisoning. However, confirmation of the effectiveness of this substance for pharmacotherapy of calcium antagonists poisoning requires further clinical research. The influence of 4-AP on calcium channels is indirect. It blocks potassium channels K1 in cytoplasm side which makes potassium to stay inside the cell leading to depolarisation and opening of voltage-dependent calcium channels.