Dose-toxicity Relationship Study for Cardiotonic Effect of Aconitine

Objective:To analyze the relationship between toxicity and cardiotonic effect of aconitine,calculating the therapeutic index(TI) of aconitine.Method: Regarding rat's electrocardiogram(ECG) change as the index,the toxicity to heart induced by aconitine was studied.Nimodipine,one of Ca2+ antagonist,was used to make heart failure model in rats.The aconitine was injected through femoral vein continuously.The effect on heart rate,+dp/dtmax,LVDP-rate pressure product(RPP) was observed.Result: Regarding RPP or +dp/dtmax as the index of ED50 and regarding PVC or CA as the index of TD50 or LD50,LD50/ED50 or TD50/ED50 was used to calculate the therapeutic index(TI) of aconitine,TI(RPP)were 1.84,17.22 and TI(+dp/dtmax)were 1.23,11.54 respectively.Conclution: Aconitine has cardiotonic effect but has toxicity to heart.TI is small.