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  (Redirected from Para-fluorobutyryl fentanyl)

4-Fluorobutyrylfentanyl (also known as 4-FBF and p-FBF) is an opioid analgesic that is an analog of butyrfentanyl and has been sold online as a designer drug.[1][2] It is closely related to 4-fluorofentanyl, which has an EC50 value of 4.2 nM for the human μ-opioid receptor.[3]

Legal status
Legal status
CAS Number
PubChem CID
Chemical and physical data
Molar mass368.487563 g/mol g·mol−1
3D model (JSmol)

Side effectsEdit

Side effects of fentanyl analogs are similar to those of fentanyl itself, which include itching, nausea and potentially serious respiratory depression, which can be life-threatening. Fentanyl analogs have killed hundreds of people throughout Europe and the former Soviet republics since the most recent resurgence in use began in Estonia in the early 2000s, and novel derivatives continue to appear.[4]

Legal statusEdit

Sweden's public health agency suggested classifying 4-fluorobutyrylfentanyl as hazardous substance on August 18, 2014.[5]

In October 2015, 4-fluorobutyrylfentanyl became a controlled substance in China.[6]

4-Fluorobutyrfentanyl is a Schedule I controlled drug in the USA since 1. February 2018.[7]

See alsoEdit


  1. ^ "para-Fluorobutyrylfentanyl". Cayman Chemical. Retrieved 15 July 2015.
  2. ^ Bäckberg, Matilda; Beck, Olof; Jönsson, Karl-Henrik; Helander, Anders (9 August 2015). "Opioid intoxications involving butyrfentanyl, 4-fluorobutyrylfentanyl, and fentanyl from the Swedish STRIDA project". Clinical Toxicology. 53 (7): 609–617. doi:10.3109/15563650.2015.1054505. ISSN 1556-3650. PMID 26083809.
  3. ^ Ulens, Chris; Boven, Maurits Van; Daenens, Paul; Tytgat, Jan (1 September 2000). "Interaction of p-Fluorofentanyl on Cloned Human Opioid Receptors and Exploration of the Role of Trp-318 and His-319 in μ-Opioid Receptor Selectivity". Journal of Pharmacology and Experimental Therapeutics. 294 (3): 1024–1033. ISSN 1521-0103. PMID 10945855.
  4. ^ Mounteney, Jane; Giraudon, Isabelle; Denissov, Gleb; Griffiths, Paul (July 2015). "Fentanyls: Are we missing the signs? Highly potent and on the rise in Europe". International Journal of Drug Policy. 26 (7): 626–631. doi:10.1016/j.drugpo.2015.04.003. PMID 25976511.
  5. ^ "Nya substanser klassas som narkotika eller hälsofarlig vara" (in Swedish). Folkhälsomyndigheten. 18 August 2015. Retrieved 21 August 2015.
  6. ^ "关于印发《非药用类麻醉药品和精神药品列管办法》的通知" (in Chinese). China Food and Drug Administration. 27 September 2015. Retrieved 1 October 2015.
  7. ^ "Schedules of Controlled Substances: Temporary Placement of Seven Fentanyl-Related Substances in Schedule I". Federal Register. 1 February 2018.