Agonist-antagonists, pharmacodynamic

Benzomorphan pharmacodynamics is dictated by molecular geometry. ( )-ll/3-Alkylbenzomorphans are more active analgesics or mixed agonist/antagonists than their ( )-l la-alkyl counterparts, and the levo antipode is very largely responsible for the narcotic properties of both a- and /3-racemates. This is hardly surprising, as a-(-)-8-hydroxy-3-methyl-6,ll-diethyl-benzomorphan has been shown to have a configuration identical to that of (—)-morphine.(179)... 

It should be noted that almost all fundamental types of adverse event have been described, including those mentioned above. These include agonist-antagonist interaction, protein-binding competition, metabolic adaptation and pharmacodynamic synergy. 

In conclusion, the investigation of peptidic and non-peptidic tool compounds for the 5 receptor have demonstrated the potential use of 5 agonists and antagonists for a variety of clinical applications, especially for the treatment of pain. Full exploitation of this potential will however only be possible with ideal non-peptidic compounds having high potency, selectivity and, above all, optimal drug metabolism and pharmacodynamic characteristics. 

Compound 79 does not induce an effect on the release of dopamine from the striatum (Figure 5. ID). The binding data together with literature data suggest that this compound is a partial dopamine D2 receptor agonist and a dopamine Di receptor antagonist.261 Therefore, the present pharmacodynamic method was not suitable to determine the relative oral bioavailability. 

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