Cyclorphan Explained

Cyclorphan is an opioid analgesic of the morphinan family that was never marketed.^[1] It acts as a μ-opioid receptor (MOR) weak partial agonist or antagonist, κ-opioid receptor (KOR) full agonist, and, to a much lesser extent, δ-opioid receptor (DOR) agonist (75-fold lower affinity relative to the KOR).^{[2] [3]} The drug was first synthesized in 1964 by scientists at Research Corporation.^{[4] [5]} In clinical trials, it had relatively long duration, good absorption, and provided strong pain relief but produced psychotomimetic effects via KOR activation, so its development was not continued.

See also

• Butorphanol
• Levomethorphan
• Levorphanol
• Nalbuphine
• Oxilorphan
• Proxorphan
• Xorphanol

Notes and References

1. Book: Maxwell Gordon. Psychopharmacological Agents. 2 December 2012. Elsevier Science. 978-0-323-15963-0. 19–.
2. Book: Linda P. Dwoskin. Emerging Targets & Therapeutics in the Treatment of Psychostimulant Abuse. 29 January 2014. Elsevier Science. 978-0-12-420177-4. 403–.
3. Book: Aldrich JV, Vigil-Cruz SC. Narcotic Analgesics . 10.1002/0471266949.bmc100 . 331–482 . Burger's Medicinal Chemistry and Drug Discovery . 7th . 2003 . 9780471266945.
4. https://patents.google.com/patent/US3285922 US Patent 3,285,922
5. Varghese V & Hudlicky T. A Short History of the Discovery and Development of Naltrexone and Other Morphine Derivatives. Chapter 6 in Natural Products in Medicinal Chemistry, Volume 60 of Methods and Principles in Medicinal Chemistry. Ed. Stephen Hanessian. John Wiley & Sons, 2013.