Remifentanil

Remifentanil is a potent synthetic opioid analgesic used primarily during anesthesia and in intensive care settings. It is a μ-opioid receptor agonist with an ultra-short duration of action due to rapid hydrolysis by nonspecific plasma and tissue esterases, not by the liver or kidneys. This metabolism gives a very short context-insensitive half-life (roughly 3–5 minutes), and analgesic effects diminish within minutes after stopping the infusion, even after long administrations. As a result, remifentanil allows precise titration and rapid recovery from opioid effects, with minimal accumulation.

It is administered intravenously as an infusion, usually started during anesthesia to provide analgesia and sometimes hemodynamic stability, and continued only as long as surgical or procedural needs persist. It is available under brand names such as Ultiva and is used in adults and children in various settings; dosing is individualized and requires close monitoring by anesthesia or critical-care professionals.

Common adverse effects include respiratory depression, bradycardia, and hypotension; other drug interactions can enhance central nervous system or respiratory depressant effects. It requires continuous monitoring of respiratory status, heart rate, and blood pressure, and resuscitation equipment should be readily available. Because of its rapid offset, abrupt discontinuation can lead to a transient surge in pain and, in some cases, opioid-induced hyperalgesia; careful planning for postoperative analgesia is recommended. Avoid use in patients with known hypersensitivity to the drug.