Systemically administered opioids are among the most powerful analgesics for treating
severe pain. Several negative side effects (respiratory depression, addiction, nausea and …

Opioids produce strong analgesia but their use is limited by a paradoxical hypersensitivity
named opioid-induced hyperalgesia (OIH) that may be associated to analgesic tolerance. In …

Opioids are the oldest and most potent drugs for the treatment of severe pain. Their clinical
application is undisputed in acute (eg, postoperative) and cancer pain, but their long-term …

Opioid receptors comprise μ (MOP), δ (DOP), κ (KOP), and nociceptin/orphanin FQ (NOP)
receptors. Opioids are agonists of MOP, DOP, and KOP receptors, whereas …

Opioids are the most effective drugs for the treatment of severe pain, but they also cause
addiction and overdose deaths, which have led to a worldwide opioid crisis. Therefore, the …

Introduction: Opioids are the oldest and most potent drugs for the treatment of severe pain,
but they are burdened by detrimental side effects such as respiratory depression, addiction …

The harmful side effects of opioid drugs such as respiratory depression, tolerance,
dependence, and abuse potential have limited the therapeutic utility of opioids for their …

Potent and clinically significant analgesic effects can be brought about by opioids acting
outside the central nervous system. Injury and inflammation of peripheral tissues leads to …

Opioid receptor antagonists increase hyperalgesia in humans and animals, which indicates
that endogenous activation of opioid receptors provides relief from acute pain; however, the …

This review summarizes recent findings on peripheral mechanisms underlying the
generation and inhibition of pain. The focus is on events occurring in peripheral injured …