[Acute poisoning by beta-blockers and by calcium inhibitors]

Abstract

beta-blockers and calcium-channel inhibitors are frequently used for self-poisoning. Propranolol and verapamil, the leading drugs in each pharmacological class, are the most toxic. They interfere with intracellular calcium concentration in muscles. Circulatory insufficiency may be due to vasodilatation, myocardial depression or severe bradycardia. If one respects a specific sequence for administration, the usual antidotes (glucagon, calcium salts, isoprenaline, epinephrine) are usually efficient. One must not underestimate the risk of worsening of an intoxication that is seen at the early stage, that occur in an old person or in a patient with heart disease, or that depress ventilation. Hence, it is important to monitor and treat these intoxications in an intensive care unit.