The pruritus of cholestasis: potential pathogenic and therapeutic implications of opioids

Opioid receptors, including the mu (μ, MOR), delta (δ, DOR), and kappa (κ, KOR) types, belong to the rhodopsin family of G protein-coupled receptors. These receptors are located throughout the central and peripheral nervous systems and in non-neuronal tissues such as macrophages and astrocytes. Opioid receptor ligands can be categorized into agonists or antagonists. Highly selective agonists include [d-Ala2, MePhe4, Gly(ol)5]-enkephalin or DAMGO for MOR, [D-Pen2, D-Pen5]-enkephalin or DPDPE for...

Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be...

Opioids are a class of drugs that mimic endogenous opioid peptides and act on opioid receptors, and help in pain relief. These compounds are classified as natural, synthetic, or semi-synthetic. Natural opioids, like morphine, codeine, and thebaine, are derived from the opium poppy plant (Papaver somniferum or Papaver album) and are termed opiates. Synthetic opioids are artificial, while semi-synthetic opioids combine natural and synthetic compounds. Morphine, a prototypical opioid, possesses a...

Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...

Diarrhea, a condition marked by frequent loose or watery bowel movements, can be triggered by multiple factors such as viral or bacterial infections, food intolerances, anxiety, medications, and digestive disorders. Symptoms may include abdominal pain, bloating, nausea, and cramping. Severe or prolonged diarrhea can lead to complications like electrolyte imbalances, malnutrition, and dehydration if left untreated.
Opioids, widely used antidiarrheal agents, mitigate diarrhea by slowing down...

Chronic pancreatitis is a progressive and irreversible inflammation of the pancreas, most often caused by long-term alcohol abuse, but it can also be related to ductal obstruction, smoking, or genetic factors.Chronic pancreatitis occurs when the pancreas is repeatedly exposed to harmful agents like alcohol, smoking, ductal obstruction, or genetic predisposition. These factors lead to the release of toxic metabolites and inflammatory cytokines, sustaining chronic inflammation in the pancreatic...