trefentanil

Trefentanil is a synthetic opioid analgesic belonging to the fentanyl family. It is an extremely potent μ-opioid receptor agonist, structurally related to fentanyl, carfentanil, and remifentanil. Like other members of this class, trefentanil acts primarily by binding to and activating the μ-opioid receptor in the central nervous system, leading to profound analgesia and sedation. Trefentanil was developed for use as an anesthetic adjunct due to its rapid onset and short duration of action. Its potency is similar or greater than that of fentanyl but less than carfentanil. Due to its high potency and risk profile (notably severe respiratory depression), it has not been widely adopted in clinical practice.