[The application of 4-aminopyridine in calcium channel inhibitors acute poisoning].

Calcium channel inhibitors have been extensively used to treat arterial hypertension, ischaemic heart disease and supraventricular rhythm irregularities. The poisonings by that category of drugs are extremely dangerous, particularly when accompanied by intoxication with other drugs affecting the circulatory function. This paper reports 3 cases of poisonings with calcium channel inhibitors (verapamil and diltiazem) in combination with angiotensin convertase inhibitors and nonselective beta-adrenolytics. Circulatory insufficiency and cardiac rhythm abnormalities were noted in all reported cases, in one in the form of ventricular bigeminy and two episodes of ventricular fibrillation, while in the two other cases in the form of 1 degree atrioventricular block. The persisting hypotonia combined with heart rhythm disturbances could not be prevented by the typical conservative treatment involving intravenous administration of infusion fluids, calcium formulations, catecholamines and atropin. The application of 4-amino-pyridine (Pymadin) caused that arterial tension and heart rate were higher, and the heart rhythm disturbances disappeared. The reported cases suggest a beneficial effect of 4-aminopyridine used to treat cases of poisonings by calcium channel inhibitors; however, up to the present time, no detailed procedures have been determined for 4-aminopyridine administration in cases like those reported above. 4-aminopyridine has not been included in the list of the antidotes approved by the WHO and, therefore, broader tests and more clinical observations are required to confirm its therapeutic value.