Synthetic Opioids

Synthetic opioids" is not a molecule or receptor but a **class of substances** synthesized in laboratories that act on opioid receptors in the brain and body, producing analgesic and euphoric effects[7][6]. Well-known examples include fentanyl, methadone, tramadol, and a large number of designer analogs such as U-47700, AH-7921, and various fentanyl derivatives[4][1]. This group encompasses structurally diverse compounds, including piperidinyl, benzamide, acetamide, piperazine, and benzimidazole classes[1][4][3]. They may act as agonists or antagonists for mu, kappa, and delta opioid receptors, but "synthetic opioids" itself does not refer to any specific biological target—rather, it is the class of compounds with opioid receptor activity that are synthesized chemically[8][2][5]. The recent proliferation of new synthetic opioids is a significant public health challenge due to unpredictable potency and composition, widespread recreational use, and overdoses associated with unregulated analogs[7][5][4]. **Summary rationale:** "Synthetic opioids" is not a canonical name or abbreviation for a therapeutic target (e.g., specific receptor, enzyme, or transporter), but a broad descriptor for a chemically synthesized drug class. Detailed molecular or receptor-level information must be attributed to individual drugs (such as fentanyl or U-47700) or the opioid receptor proteins themselves (such as mu-opioid receptor), not the class term "synthetic opioids"[7][2][8].

Other names

Synthetic opioidsfentanyl analogsnon-fentanyl synthetic opioidsbenzimidazole-opioidsnitazenesdesigner opioidsnovel psychoactive opioidsnew psychoactive synthetic opioids