The drug buprenorphine was developed using the agonist-antagonist construct. It is a promising drug for the detoxification of heroin addicts because it produces less intensive intense withdrawal symptoms, is relatively non-toxic, and can be used by outpatients. It is also being studied as a therapy for individuals dependent on cocaine.
Metopan Diagram reference:
C.K. Himmelsbach. Journal of Pharmacology and Experimental Therapeutics, Vol. 67, No. 2, October 1939, pp. 239-249.
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Metopan Diagram
The bottom shows that metopan (methyldihydromorphinone) fails to block morphine withdrawal symptoms completely (center) and that its own withdrawal syndrome is milder than that produced by morphine (right)
C.K. Himmelsbach. Journal of Pharmacology and Experimental Therapeutics, Vol. 67, No. 2, October 1939, pp. 239-249.
Using Opiates to Learn About the Brain
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The discovery that the brain produces its own chemicals which act similarly to opiates opened avenues for learning how the brain transmits signals and manages thought, feeling, and action. It opened new ways to study diseases as well.
In 1984, using their opium-derived narcotic antagonist called cyclofoxy, Dr. Kenner Rice's group at LMC and their NIH associates reported the first definitive image of opiate receptors in a living primate brain. They are now using this drug and other research tools to investigate central nervous system disorders, the regulation of the immune system, and possible new treatments for drug dependence.
Besides being painkillers, certain narcotic drugs and antagonists (drugs which block the actions of other drugs by combining with and blocking receptors) are used to study opiate receptor sites in normal humans. Parallel studies in patients with schizophrenia, bulimia, sexual dysfunction, and opiate and cocaine addition will provide insight into the role of opioid receptors in these disorders. A PET (positron emission tomography) scan shows cyclofoxy binding to receptors in the caudate nucleus, thalamus and other areas of the brain (red to orange areas).
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Light portions in the center of the brain images show that cyclofoxy is binding to opiate receptors in a baboon brain