Pharmacology of sedative-analgesic agents: dexmedetomidine, remifentanil, ketamine, volatile anesthetics, and the role of peripheral mu antagonists.

In this article, the authors discuss the pharmacology of sedative-analgesic agents like dexmedetomidine, remifentanil, ketamine, and volatile anesthetics. Dexmedetomidine is a highly selective alpha-2 agonist that provides anxiolysis and cooperative sedation without respiratory depression. It has organ protective effects against ischemic and hypoxic injury, including cardioprotection, neuroprotection, and renoprotection. Remifentanil is an ultra-short-acting opioid that acts as a mu-receptor agonist. Ketamine is a nonbarbiturate phencyclidine derivative and provides analgesia and apparent anesthesia with relative hemodynamic stability. Volatile anesthetics such as isoflurane, sevoflurane, and desflurane are in daily use in the operating room in the delivery of general anesthesia. A major advantage of these halogenated ethers is their quick onset, quick offset, and ease of titration in rendering the patient unconscious, immobile, and amnestic.