[Effect of levomepromazine on atrioventricular conduction tissue (author's transl)]

The effect of levomepromazine on sinusal automaticity, myocardial excitability and auriculoventricular conduction have been studied in dogs by measuring the spontaneous heart rate, the effective refractory period of the conduction system, the time of auriculonodal and infrahisian conduction. Chloralose-anaesthetized dogs were administered 5 mg/kg levomepromazine via IV route and 10 mg/kg one hour later. While sinusal automaticity is never altered, the other parameters studied were modified only when high doses were used. Therefore these quinidine-like effects are very unlikely to come up even following suicidal massive ingestion of levomepromazine.