Opiate pharmacological properties

The pharmacological properties of the cloned opiate receptors are similar to the characteristics of the endogenously expressed receptors [9, 36, 45]. The binding of opiates to the cloned receptors is stereoselective and the antagonist naloxone interacts with all three of the cloned receptors, although naloxone had much lower af-... 

Careful analyses of the pharmacologic properties of 3H-hailucinogen binding sites indicated that they may correspond to 5-HT receptors (in the case of 3H-LSD), sigma opiate receptors (in the case of 3H-PCP), or even GABA receptors (in the case of 3H-muscimol). Such data recall that hallucinogens should interfere markedly with the metabolism of neurotransmitters in the CNS. These hallucinogen-induced alterations of neurotransmitter metabolism and functions are summarized below. 

The capsules and stems of Papaver somniferum contain opiate alkaloids essential in medicine. They are classified into two groups, phenanthrene types (morphine, codeine, thebaine) and benzylisoquinoline types [papaverine and noscapine(narcotine)]. These two types of alkaloids show sharply specific pharmacological properties. It is noteworthy that morphinane alkaloids are formed from (-)-(/ )-reticuline, whereas most other alkaloids derive from (-l-)-(5)-re-ticuline 11). 

Cocaine and other stimulant drugs are often taken in combination with other drugs, particularly alcohol and opiates. Laboratory studies in humans have shown that alcohol can enhance and prolong the subjective pleasure associated with cocaine, and this is likely the basis for their frequent association. Recent studies have revealed that when cocaine is taken with alcohol, a new compound called cocaethylene is formed in the body. Cocaethylene has pharmacological properties similar to cocaine, but it may be more toxic. Many cases of cocaine overdose may in fact involve cocaethylene toxicity caused by combining cocaine and alcohol (Raven, Necessary, Danluck, Ettenberg,... 

Burke TR Jr, Bajwa BS, Jacobson AE, et ai. Probes for narcotic receptor mediated phenomena. 7. Synthesis and pharmacological properties of irreversible ligands specific for p or 5 opiate receptors. J Med Chem 1984 27 1570-1574. 

Profound effects on pharmacological activity are exerted when the N-substituent is varied (p 117) These changes in opioid responses parallel those seen in other rigid opiates Groups such as N-allyl, N-CPM, and N-CBM tend to endow the molecule with antagonist properties, whereas N-Me and N-phenethyl are endowed with agonist properties... 

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