Methods, agents, and devices to treat medical conditions through local chemical neuromodulation of the autonomic nervous system are described. Drug formulations may be injected at or near ganglia, nerve plexi, ganglionated plexi, and nerves to treat different diseases. Target sites for the treatment of cardiac and other disease conditions may include extrinsic stellate (cervicothoracic) and cervical ganglia of the sympathetic chain, and intrinsic cardiac nerves and ganglionated plexi innervating the myocardium.