has role is deprotonated form of is enantiomer of metabolite opioid analgesic adrenergic uptake inhibitor serotonergic antagonist muscarinic antagonist nicotinic antagonist serotonin uptake inhibitor antitussive mu-opioid receptor agonist kappa-opioid receptor agonist NMDA receptor antagonist delta-opioid receptor agonist capsaicin receptor antagonist 2-[(dimethylamino)methyl]-1-(3-methoxyphenyl)cyclohexanol (R,R)-tramadol A 2-[(dimethylamino)methyl]-1-(3-methoxyphenyl)cyclohexanol in which both stereocentres have <i>R</i>-configuration; the (<i>R</i>,<i>R</i>)-enantiomer of the racemic opioid analgesic tramadol, it exhibits ten-fold higher analgesic potency than the (<i>S</i>,<i>S</i>)-enantiomer. CHEBI:75725 (S,S)-tramadol (R,R)-tramadol(1+)