Cardiovascular pharmacology of local anaesthetics.

Although most local anaesthetic drugs are generally regarded as vasodilators at their site of injection, they produce systemic effects characterized by increases in peripheral resistance, cardiac output, arterial pressure heart rate. The direct depressive effects of the drugs are counterbalanced by increased sympathetic activity. There is evidence that many local anaesthetic agents increase the myogenic tone of certain vascular beds. A proper understanding of these phenomena could lead to improvements in the development of new local anaesthetic agents and appropriate vasoconstrictors.