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Serotonin Antagonists
A serotonin antagonist, or serotonin receptor antagonist, is a drug used to inhibit the action at serotonin (5-HT) receptors. Types 5-HT2A antagonists Antagonists of the 5-HT2A receptor are sometimes used as atypical antipsychotics (contrast with typical antipsychotics, which are purely dopamine antagonists). They include, but are not limited to: * Cyproheptadine blocks 5-HT2A, H1 and is a mild anticholinergic. * Methysergide is a 5-HT2A antagonist and nonselective 5-HT1 receptor blocker. It causes retroperitoneal fibrosis and mediastinal fibrosis. * Quetiapine blocks 5-HT2A, 5-HT1A, dopamine receptors D1 and D2, histamine receptor H1, and A1 adrenoreceptors. 5-HT2A/2C antagonists * Ketanserin Antihypertensive. Blocks 5-HT2A, 5-HT2C and Alpha 1 (A1) adrenoreceptors. * Risperidone antipsychotic * Trazodone 5-HT3 antagonists Another subclass consists of drugs selectively acting at the 5-HT3 receptors, and thus are known as 5-HT3 antagonists. They are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin 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, including many antidepressants, antipsychotics, anorectics, antiemetics, gast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HRH1
The H1 receptor is a histamine receptor belonging to the family of rhodopsin-like G-protein-coupled receptors. This receptor is activated by the biogenic amine histamine. It is expressed in smooth muscles, on vascular endothelial cells, in the heart, and in the central nervous system. The H1 receptor is linked to an intracellular G-protein (Gq) that activates phospholipase C and the inositol triphosphate (IP3) signalling pathway. Antihistamines, which act on this receptor, are used as anti-allergy drugs. The crystal structure of the receptor has been determined (shown on the right/below) and used to discover new histamine H1 receptor ligands in structure-based virtual screening studies. Function The expression of NF-κB, the transcription factor that regulates inflammatory processes, is promoted by the constitutive activity of the H1 receptor as well as by agonists that bind at the receptor. H1-antihistamines have been shown to attenuate NF-κB expression and mitigate certain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ondansetron
Ondansetron, sold under the brand name Zofran among others, is a medication used to prevent nausea and vomiting caused by cancer chemotherapy, radiation therapy, or surgery. It is also effective for treating gastroenteritis. It can be given by mouth or by injection into a muscle or into a vein. Common side effects include diarrhea, constipation, headache, sleepiness, and itchiness. Serious side effects include QT prolongation and severe allergic reaction. It appears to be safe during pregnancy but has not been well studied in this group. It is a serotonin 5-HT3 receptor antagonist. It does not have any effect on dopamine receptors or muscarinic receptors. Ondansetron was patented in 1984 and approved for medical use in 1990. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2020, it was the 83rd most commonly prescribed medication in the United States, with more than 8million prescriptions. Medical uses A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granisetron
Granisetron is a serotonin 5-HT3 receptor antagonist used as an antiemetic to treat nausea and vomiting following chemotherapy and radiotherapy. Its main effect is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata. It does not have much effect on vomiting due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors. Granisetron was developed by chemists working at the British drug company Beecham around 1985 and is available as a generic. It is produced by Roche Laboratories under the trade name Kytril. The drug was approved in the United Kingdom in 1991 and in United States in 1994 by the FDA. A granisetron transdermal patch with the trade name Sancuso was approved by the US FDA on September 12, 2008. Sancuso is manufactured by 3M Drug Delivery Systems for Kyowa Kirin, Inc. It was patented in 1985 and approved for medical use in 1991. It is on the World Health ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolasetron
Dolasetron (trade name Anzemet) is a serotonin 5-HT3 receptor antagonist used to treat nausea and vomiting following chemotherapy. Its main effect is to reduce the activity of the vagus nerve, which is a nerve that activates the vomiting center in the medulla oblongata. It does not have much antiemetic effect when symptoms are due to motion sickness. This drug does not have any effect on dopamine receptors or muscarinic receptors. Dolasetron breaks down slowly, staying in the body for a long time. One dose is usually administered once or twice daily and lasts 4 to 9 hours. This drug is removed from the body by the liver and kidneys. It was patented in 1986 and approved for medical use in 2002. It is on the World Health Organization's List of Essential Medicines. Medical uses * Chemotherapy-induced nausea and vomiting ** 5-HT3 receptor antagonists are the primary drugs used to treat and prevent chemotherapy-induced nausea and vomiting. Many times they are given intravenously abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postoperative Nausea And Vomiting
Postoperative nausea and vomiting (PONV) is the phenomenon of nausea, vomiting, or retching experienced by a patient in the postanesthesia care unit (PACU) or within 24 hours following a surgical procedure. PONV affects about 10% of the population undergoing general anaesthesia each year. PONV can be unpleasant and lead to a delay in mobilization and food, fluid, and medication intake following surgery. Cause Emetogenic drugs commonly used in anaesthesia include nitrous oxide, physostigmine, and opioids. The intravenous anaesthetic propofol is currently the least emetogenic general anaesthetic. These medications are thought to stimulate the chemoreceptor trigger zone. This area is on the floor of the fourth ventricle and is effectively outside of the blood-brain barrier, which makes it incredibly sensitive to toxin and pharmacological stimulation. Several neurotransmitters are known, such as histamine, dopamine, serotonin, acetylcholine, and the more recently discovered neurokinin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy-induced Nausea And Vomiting
Chemotherapy-induced nausea and vomiting (CINV) is a common side-effect of many cancer treatments. Nausea and vomiting are two of the most feared cancer treatment-related side effects for cancer patients and their families. In 1983, Coates et al. found that patients receiving chemotherapy ranked nausea and vomiting as the first and second most severe side effects, respectively. Up to 20% of patients receiving highly emetogenic agents in this era postponed, or even refused, potentially curative treatments. Since the 1990s, several novel classes of antiemetics have been developed and commercialized, becoming a nearly universal standard in chemotherapy regimens, and helping to better manage these symptoms in a large portion of patients. Efficient mediation of these unpleasant and sometimes crippling symptoms results in increased quality of life for the patient, and better overall health of the patient, and, due to better patient tolerance, more effective treatment cycles. Types There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT3 Antagonist
The 5-HT3 antagonists, informally known as "setrons", are a class of drugs that act as receptor antagonists at the 5-HT3 receptor, a subtype of serotonin receptor found in terminals of the vagus nerve and in certain areas of the brain. With the notable exceptions of alosetron and cilansetron, which are used in the treatment of irritable bowel syndrome, all 5-HT3 antagonists are antiemetics, used in the prevention and treatment of nausea and vomiting. They are particularly effective in controlling the nausea and vomiting produced by cancer chemotherapy and are considered the gold standard for this purpose. The 5-HT3 antagonists may be identified by the suffix -setron, and are classified under code A04AA of the 's Anatomical Therapeutic Chemical Classification System. Medical uses 5-HT3 antagonists are most effective in the prevention and treatment of chemotherapy-induced nausea and vomiting (CINV), especially that caused by highly emetogenic drugs such as cisplatin; when use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT3 Receptor
The 5-HT3 receptor belongs to the Cys-loop superfamily of ligand-gated ion channels (LGICs) and therefore differs structurally and functionally from all other 5-HT receptors (5-hydroxytryptamine, or serotonin receptors) which are G protein-coupled receptors. This ion channel is cation-selective and mediates neuronal depolarization and excitation within the central and peripheral nervous systems. As with other ligand gated ion channels, the 5-HT3 receptor consists of five subunits arranged around a central ion conducting pore, which is permeable to sodium (Na), potassium (K), and calcium (Ca) ions. Binding of the neurotransmitter 5-hydroxytryptamine (serotonin) to the 5-HT3 receptor opens the channel, which, in turn, leads to an excitatory response in neurons. The rapidly activating, desensitizing, inward current is predominantly carried by sodium and potassium ions. 5-HT3 receptors have a negligible permeability to anions. They are most closely related by homology to the nicotinic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trazodone
Trazodone, sold under many brand names, is an antidepressant medication. It is used to treat major depressive disorder, anxiety disorders, and difficulties with sleep. The medication is taken orally. Common side-effects include dry mouth, feeling faint, vomiting, and headache. More serious side effects may include suicide, mania, irregular heart rate, and pathologically prolonged erections. It is unclear if use during pregnancy or breastfeeding is safe. It is a phenylpiperazine compound of the serotonin antagonist and reuptake inhibitor (SARI) class. Trazodone also has sedating effects. Trazodone was approved for medical use in the United States in 1981. It is available as a generic medication. In 2020, it was the 21st most commonly prescribed medication in the United States, with more than 26million prescriptions. Medical uses Depression The primary use of trazodone is the treatment of unipolar major depression with or without anxiety. Data from open and double-blind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Risperidone
Risperidone, sold under the brand name Risperdal among others, is an atypical antipsychotic used to treat schizophrenia and bipolar disorder. It is taken either by mouth or by injection (subcutaneous or intramuscular). The injectable versions are long-acting and last for 2–4 weeks. Common side effects include extrapyramidal symptoms, movement problems, sedation, sleepiness, dizziness, trouble seeing, constipation, and increased weight. Serious side effects may include the potentially permanent movement disorder tardive dyskinesia, as well as neuroleptic malignant syndrome, an increased risk of suicide, and hyperglycemia, high blood sugar levels. In older people with psychosis as a result of dementia, it may increase the risk of death. It is unknown if it is safe for use in pregnancy. Its mechanism of action is not entirely clear, but is believed to be related to its action as a dopamine antagonist, dopamine and serotonin antagonist. Study of risperidone began in the late 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenoreceptors
The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta blockers, beta-2 (β2) agonists and alpha-2 (α2) agonists, which are used to treat high blood pressure and asthma, for example. Many cells have these receptors, and the binding of a catecholamine to the receptor will generally stimulate the sympathetic nervous system (SNS). The SNS is responsible for the fight-or-flight response, which is triggered by experiences such as exercise or fear-causing situations. This response dilates pupils, increases heart rate, mobilizes energy, and diverts blood flow from non-essential organs to skeletal muscle. These effects together tend to increase physical performance momentarily. History By the turn of the 19th century, it was agreed that the stimulation of sympathetic nerves could cause di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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