[[Opioids]] (''e.g.''''' butorphanol, buprenorphine''') are classified either as (full) agonists, agonist-antagonists (partial agonists) or antagonists based on differing affinities and efficacy at μ-, κ- and δ-opioid receptors, which results in activation of descending inhibitory pathways and reduction in the transmission of nociceptive signals to higher centres in the brain. Opioid | [[Opioids]] (''e.g.''''' butorphanol, buprenorphine''') are classified either as (full) agonists, agonist-antagonists (partial agonists) or antagonists based on differing affinities and efficacy at μ-, κ- and δ-opioid receptors, which results in activation of descending inhibitory pathways and reduction in the transmission of nociceptive signals to higher centres in the brain. Opioid |