Alfentanil: A Comprehensive Pharmacological and Clinical Monograph

I. Executive Summary

Alfentanil is a potent, synthetic, short-acting opioid analgesic classified as a small-molecule derivative of fentanyl.[1] Its pharmacological profile is distinguished by an exceptionally rapid onset of action and a brief, predictable duration, characteristics that define its specific niche within clinical anesthesiology and critical care.[1] As a selective agonist of the μ-opioid receptor, Alfentanil exerts powerful analgesic and sedative effects by modulating neurotransmission within the central nervous system.[3] These properties are a direct result of its unique physicochemical nature, particularly a low pKa that facilitates rapid transit across the blood-brain barrier.[2]

The primary clinical utility of Alfentanil is centered on scenarios requiring intense, titratable analgesia with a swift recovery profile. It is approved by the U.S. Food and Drug Administration (FDA) as an analgesic adjunct for the induction and maintenance of general anesthesia, as a primary anesthetic agent for certain surgical procedures, and as the analgesic component for monitored anesthesia care (MAC).[1] Its rapid action makes it particularly valuable for blunting the profound hemodynamic stress responses associated with noxious stimuli of short duration, such as endotracheal intubation.[5]