O-2050 is a drug that is a classical cannabinoid derivative, which acts as a silent antagonist for the CB1receptor. This gives it an advantage in research over many commonly used cannabinoid antagonists such as rimonabant, which at higher doses act as inverse agonists at CB1 as well as showing off-target effects. However while O-2050 acts as a silent antagonist in vitro, some tests in vivo have suggested it may show agonist activity under certain circumstances.
^Martin et al. SULFONAMIDE CANNABINOID AGONISTS AND ANTAGONISTS. US Patent 7279500, Oct 9 2007
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