Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0278080 (physical dependence)
 1,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although controversial, opioid analgesics have been prescribed for patients with chronic facial pain. Based primarily on survey data and a few well-controlled clinical trials, long-term opioid treatment provides adequate pain reduction in 41% to 100% of patients with chronic nonmalignant pain. However, only 25% of chronic facial pain patients reported adequate pain relief with chronic opioid treatment. Work, home, and school function are generally reestablished or maintained during chronic opioid treatment, but 25% to 38% of patients remain dysfunctional, and one study indicated that 20% of patients became dysfunctional during treatment. Chronic opioid treatment is associated with many transient side effects; constipation, dizziness, nausea, vomiting, itching, and fatigue have been reported in 5% to 42% of patients taking opioids over 1 year. Although survey studies suggest that the risks of addiction are low in typical patients, drug abuse rates up to 17.3% and prescription abuse rates up to 27.6% were reported within groups of chronic opioid users. Chronic opioid use induces analgesic tolerance and physical dependence, which may result in a serious abstinence syndrome in users and children born to users. Chronic opioid use also may induce harmful immune system changes, diminish cognitive and motor function, and produce nociceptive hyperexcitability. This article shows that the use of long-term opioids for chronic facial pain is not justified based on the available data. Despite these perceived problems, there is anecdotal evidence that chronic facial pain patients will respond positively to opioid analgesics. In our experience, the pain assessment scale and a modification of the World Health Organization's three-step analgesic ladder, which prescribes nonopioid analgesics, can be the starting point for the successful management of chronic facial pain.
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PMID:The use of nonopioid drugs in management of chronic orofacial pain. 973 70

Following the identification of the nociceptin/orphanin FQ (N/OFQ) peptide (NOP) as an endogenous ligand for the NOP receptor, ample evidence has revealed unique functional profiles of the N/OFQ-NOP receptor system. NOP receptors are expressed in key neural substrates involved in pain and reward modulation. In nonhuman primates (NHPs), NOP receptor activation effectively exerts antinociception and anti-hypersensitivity at the spinal and supraspinal levels. Moreover, NOP receptor activation inhibits dopaminergic transmission and synergistically enhances mu-opioid peptide (MOP) receptor-mediated analgesia. In this article, we have discussed the functional profiles of ligands with dual NOP and MOP receptor agonist activities and highlight their optimal functional efficacy for pain relief and drug abuse treatment. Through coactivation of NOP and MOP receptors, bifunctional NOP/MOP receptor "partial" agonists (e.g., AT-121, BU08028, and BU10038) reveal a wider therapeutic window with fewer side effects. These newly developed ligands potently induce antinociception without MOP receptor agonist-associated side effects such as abuse potential, respiratory depression, itching sensation, and physical dependence. In addition, in both rodent and NHP models, bifunctional NOP/MOP receptor agonists can attenuate reward processing and/or the reinforcing effects of opioids and other abused drugs. While a mixed NOP/opioid receptor "full" agonist cebranopadol is undergoing clinical trials, bifunctional NOP/MOP "partial" agonists exhibit promising therapeutic profiles in translational NHP models for the treatment of pain and opioid abuse. This class of drugs demonstrates the therapeutic advantage of NOP and MOP receptor coactivation, indicating a greater potential for future development.
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PMID:Therapeutic potentials of NOP and MOP receptor coactivation for the treatment of pain and opioid abuse. 3225 40

Despite similar distribution patterns and intracellular events observed in the nociceptin/ orphanin FQ peptide (NOP) receptor and other opioid receptors, NOP receptor activation displays unique pharmacological profiles. Several researchers have identified a variety of peptide and nonpeptide ligands to determine the functional roles of NOP receptor activation and observed that NOP receptor- related ligands exhibit pain modality-dependent pain processing. Importantly, NOP receptor activation results in anti-nociception and anti-hypersensitivity at the spinal and supraspinal levels regardless of the experimental settings in non-human primates (NHPs). Given that the NOP receptor agonists synergistically enhance mu-opioid peptide (MOP) receptor agonist-induced anti-nociception, it has been hypothesized that dual NOP and MOP receptor agonists may display promising functional properties as analgesics. Accumulating evidence indicates that the mixed NOP/opioid receptor agonists demonstrate favorable functional profiles. In NHP studies, bifunctional NOP/MOP partial agonists (e.g., AT-121, BU08028, and BU10038) exerted potent anti-nociception via NOP and MOP receptor activation; however, dose-limiting adverse effects associated with the MOP receptor activation, including respiratory depression, itch sensation, physical dependence, and abuse liability, were not observed. Moreover, a mixed NOP/opioid receptor agonist, cebranopadol, presented promising outcomes in clinical trials as a novel analgesic. Collectively, the dual agonistic actions on NOP and MOP receptors, with appropriate binding affinities and efficacies, may be a viable strategy to develop innovative and safe analgesics.
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PMID:Nociceptin/Orphanin FQ Peptide Receptor-Related Ligands as Novel Analgesics. 3238 33