Mesaconitine is a diterpene alkaloid, from the plants of the Aconitum genus, Ranunculaceae. Mesaconitine is a centrally acting analgesic without affinity to opioid receptors. It has been reported that the antinociception is due to an interaction with the noradrenergic system. As a neurotoxic, it opens the TTX-sensitive Na+ channels in the heart and other tissues and induces arrhythmia. The activity of Mesaconitine, which is a chemical analog of Aconitine, on TTX sensitive Na+ channels in the heart and other tissues is stronger than that of Aconitine. The duration of its neurotoxic effect is shorter. It possesses an hypotensive activity. The hypotensive action is not inhibited by an adrenergic b-blocker but abolished with muscarinic blocker. It may be partially mediated by a muscarinic mechanism. Mesaconitine binds with high affinity to the open state of the voltage-sensitive sodium channels at site 2, thereby causing a persistent activation of the sodium channels, which become refractory to excitation.