Comparison of anti-arrhythmic activities of valproic acid derivatives in animals

The anti-arrhythmic activities of valproic acid derivatives were compared in animal models. The ig LD50 of sodium valproate (SV), magnesium valproate (MV) and valpramide (Val) in mice were 904, 966 and 438 mg/kg, respectively. The efficacies of SV, MV and Val against the arrhythmia induced by iv BaCla in anesthetized rats at equitoxic doses were 5/10, 5/10 and 8/10 by ig, and 5/10 7/10 and 10/10 by ip respectively. When the doses of ouabain necessary to induce arrhythmia in anesthetized guinea pigs were increased, the electrical ventricular fibrillation thresholds in anesthetized rabbits were raised and the functional refractory period of isolated guinea pig left atria was pro-longed, the effects of MV were all stronger than those of SV. The anti-arrhythmic activities of magnesium sulfate were weaker than that of SV and MV.