[Antinociceptive effects of landiolol and esmolol]

Besides its cardioinhibitory effects, short-acting beta1-adrenergic receptor antagonists, landiolol and esmolol are reported to exert antinociceptive and anesthetic sparing effects in animal and human subjects. For example, esmolol reduces the anesthetic requirements for skin incision during propofol/N2O and morphine anesthesia in human and inhibits nociceptive responses following formalin injection in rats. It is also suggested that landiolol decreases BIS response to tracheal intubation during sevoflurane anesthesia. Several possible mechanisms, such as changing pharmacokinetics of opioid and implication with inhibitory G protein, for short-acting beta1-adrenergic receptor antagonists to produce antinociceptive effects were proposed. However, direct mechanism underling antinociceptive effects of short-acting beta1-adrenergic receptor antagonists has not been fully established. The merits to use short-acting beta1-adrenergic receptor antagonists as anesthetic adjuvants could be to reduce anesthetic and opioid requirements (thus, to avoid its side effects such as nausea and vomiting), to maintain hemodynamic stability, and to achieve early recovery from anesthesia. Administration of a sufficient dose of a short-acting beta1-adrenergic receptor antagonist, for example by neuraxial route, may potentially be a new treatment strategy for the perioperative pain, although further study is necessary to establish its efficacy and toxicity. Short-acting beta1-adrenergic receptor antagonists will be used as agents for antinociception in future.