[New aspects of common antagonists used in the perioperative period: preface and comments]

Anesthesia is a state made by multiple pharmacological agents that affect the functions of central, peripheral and autonomic nervous systems. Antagonists are often used to reverse the effects of anesthetic agents, muscle relaxants, and so forth. Antagonists often have side effects other than their specific antagonistic effect. Some side effects may be clinically useful. Ketamine was found to be a NMDA receptor antagonist. Ketamine potentially has neuroprotective, and anti-tumor effect. Local anesthetic agent also has been known to have anti-NMDA receptor effect. Although the mechanisms of local anesthetics to prevent or treat chronic pain have not been clearly elucidated, local anesthetics may have a place in the treatment of chronic pain. Naloxone may have spinal protective effects when used during thoracic aortic aneurysm surgery and stent placement. Peripherally and centrally active anticholinesterase agents have unique effects. Centrally active anticholinesterase agents such as donepezil and revastigmine, and galantamine have been used to treat patients with Alzheimer's disease. These agents may antagonize the effects of non-depolarizing muscle relaxants. Flumazenil may have adverse effects in patients on chronic benzodiazepines and tricyclic or tetracyclic antidepressants. Because sugammadex has little adverse effects, it has become a popular agent to reverse muscle relaxation by rocuronium in Japan.