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Peripherally Selective Drug
Peripherally selective drugs have their primary mechanism of action outside of the central nervous system (CNS), usually because they are excluded from the CNS by the blood–brain barrier. By being excluded from the CNS, drugs may act on the rest of the body without producing side-effects related to their effects on the brain or spinal cord. For example, most opioids cause sedation when given at a sufficiently high dose, but peripherally selective opioids can act on the rest of the body without entering the brain and are less likely to cause sedation. These peripherally selective opioids can be used as antidiarrheals, for instance loperamide (Imodium). Mechanisms of peripheral selectivity include physicochemical hydrophilicity and large molecular size, which prevent drug permeation through the lipid bilayer cell membranes of the blood–brain barrier, and efflux out of the brain by blood–brain barrier transporters such as P-glycoprotein among many others. Transport out of the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilateria, bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and Coelenterata, diploblasts. It is a structure composed of nervous tissue positioned along the Anatomical_terms_of_location#Rostral,_cranial,_and_caudal, rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain, though precursor structures exist in onychophorans, gastropods and lancelets. The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cetirizine
Cetirizine is a second-generation antihistamine, second-generation Peripherally selective antihistamine used to treat allergic rhinitis (hay fever), dermatitis, and urticaria (hives). It is taken by mouth. Effects generally begin within thirty minutes and last for about a day. The degree of benefit is similar to other antihistamines such as diphenhydramine, which is a first-generation antihistamine. Common side effects include sleepiness, dry mouth, headache, and abdominal pain. The degree of sleepiness that occurs is generally less than with first-generation antihistamines because second-generation antihistamines are more selective for the Histamine H1 receptor, H1 receptor. Compared to other second-generation antihistamines, cetirizine can cause drowsiness. Among second-generation antihistamines, cetirizine is more likely than fexofenadine and loratadine to cause drowsiness. Use in pregnancy appears safe, but use during breastfeeding is not recommended. The medication works ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Ileus
Ileus is a disruption of the normal propulsive ability of the intestine. It can be caused by lack of peristalsis or by mechanical obstruction. The word 'ileus' derives . The term 'subileus' refers to a partial obstruction. Signs and symptoms Symptoms of ileus include, but are not limited to: * moderate to severe, diffuse abdominal pain * constipation * abdominal distension * nausea/vomiting, especially after meals * vomiting of bilious fluid (green or yellowish-green in colour) * flatulence and/or lack of bowel movement * excessive belching Cause Decreased propulsive ability may be broadly classified as caused either by bowel obstruction or by intestinal atony or paralysis. However, instances with symptoms and signs of a bowel obstruction occur, but with the absence of a mechanical obstruction, mainly in acute colonic pseudo-obstruction, Ogilvie's syndrome. In 2023 the US FDA reported gastrointestinal ileus as an adverse effect of the medication semaglutide, with frequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Receptor Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves ." '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, beta b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
μ-opioid Receptor
The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta-endorphin, but a low affinity for dynorphins. They are also referred to as μ(''mu'')-opioid peptide (MOP) receptors. The prototypical μ-opioid receptor agonist is morphine, the primary psychoactive alkaloid in opium and for which the receptor was named, with Mu (letter), mu being the first letter of Morpheus, the compound's namesake in the original Greek. It is an inhibitory G-protein coupled receptor that activates the Gi alpha subunit, Gi alpha subunit, inhibiting adenylate cyclase activity, lowering Cyclic adenosine monophosphate, cAMP levels. Structure The structure of the inactive μ-opioid receptor has been determined with the antagonists Beta-Funaltrexamine, β-FNA and alvimopan. Many structures of the active state are also available, with agonists including DAMGO, Β-Endorphin, β-endorphin, fentanyl and morphine. The structure with the agonist BU72 has the h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Alvimopan
Alvimopan (trade name Entereg) is a drug which behaves as a peripherally acting μ-opioid receptor antagonist. With the limited ability to cross the blood–brain barrier and reach the μ-opioid receptors of the central nervous system, the clinically undesirable effects of centrally acting opioid antagonists (like reversal of opioid-mediated analgesia) are avoided without affecting the intended blockade of μ-opioid receptors in the gastrointestinal tract. It is currently only Food and Drug Administration approved for the treatment of postoperative ileus which it received in May 2008. Medical uses Alvimopan is indicated in people to avoid postoperative ileus following partial large or small bowel resection with primary anastomosis. Alvimopan accelerates the gastrointestinal recovery period as defined by time to first bowel movement or flatus.Alvimopan Product Label as approved by the FDA on May 20, 2008. Adverse effects There is a potential risk of myocardial infarction in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
5-HT2A Receptor
The 5-HT2A receptor is a subtype of the 5-HT2 receptor, 5-HT2 receptor that belongs to the serotonin receptor family and functions as a GPCR, G protein-coupled receptor (GPCR). It is a cell surface receptor that activates multiple intracellular signalling cascades. Like all 5-HT2 receptors, the 5-HT2A receptor is coupled to the Gq protein, Gq/G11 signaling pathway. It is the primary excitatory receptor subtype among the serotonin-responsive GPCRs. The 5-HT2A receptor was initially noted for its central role as the primary target of serotonergic psychedelic drugs such as LSD and psilocybin mushrooms. It later regained research prominence when found to mediate, at least in part, the effects of many antipsychotic drugs, particularly atypical antipsychotic, atypical antipsychotics. Downregulation of post-synaptic 5-HT2A receptors is an adaptive response triggered by chronic administration of selective serotonin reuptake inhibitors (SSRIs) and atypical antipsychotics. Elevated 5-HT2A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Serotonin
Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, memory, and physiological processes such as vomiting and vasoconstriction. In the CNS, serotonin regulates mood, appetite, and sleep. Most of the body's serotonin—about 90%—is synthesized in the gastrointestinal tract by enterochromaffin cells, where it regulates intestinal movements. It is also produced in smaller amounts in the brainstem's raphe nuclei, the skin's Merkel cells, pulmonary neuroendocrine cells, and taste receptor cells of the tongue. Once secreted, serotonin is taken up by platelets in the blood, which release it during clotting to promote vasoconstriction and platelet aggregation. Around 8% of the body's serotonin is stored in platelets, and 1–2% is found in the CNS. Serotonin acts as both a vasoconstrictor and vas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
AL-34662
AL-34662 is an indazole derivative drug that is being developed for the treatment of glaucoma. It acts as a selective serotonin 5-HT2 receptor agonist, including of the 5-HT2A, 5-HT2B, and 5-HT2C receptors (affinity () = 14.5, 8.1, and 3.0nM, respectively). The serotonin 5-HT2A receptor is the same target as that of psychedelic drugs like psilocin. Unlike these drugs however, AL-34662 was designed specifically as a peripherally selective drug, which does not cross the blood–brain barrier. This means that AL-34662 can exploit a useful side effect of the hallucinogenic 5-HT2A receptor agonists, namely reduction in intra-ocular pressure and hence relief from the symptoms of glaucoma, but without causing the psychedelic effects that make centrally active serotonin 5-HT2A receptor agonists unsuitable for clinical use. In animal studies, AL-34662 has been shown to be potent and effective in the treatment of symptoms of glaucoma, with minimal side effects. Peripherally acting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Agonist
An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an Receptor antagonist, antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology The word originates from the Ancient Greek, Greek word (''agōnistēs''), "contestant; champion; rival" < (''agōn''), "contest, combat; exertion, struggle" < (''agō''), "I lead, lead towards, conduct; drive." Types of agonists Receptor (biochemistry), Receptors can be activated by either endogenous agonists (such as hormones and neurotransmitters) or exogenous agonists (such as medication, drugs), resulting in a biological response. A physiological agonism an ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Serotonin Receptor
5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in multiple tissues including the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin (i.e., 5-hydroxytryptamine, hence "5-HT") receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand. The serotonin receptors modulate the release of many neurotransmitters, including glutamate, GABA, dopamine, epinephrine / norepinephrine, and acetylcholine, as well as many hormones, including oxytocin, prolactin, vasopressin, cortisol, corticotropin, and substance P, among others. Serotonin receptors influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, and thermoregulation. They are the target of a variety of pharmaceutical and recreational drugs, inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
