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Serotonin Receptor Antagonist
A serotonin antagonist, or serotonin receptor antagonist, is a drug used to inhibit the action of serotonin and serotonergic drugs at serotonin receptor, serotonin (5-HT) receptors. Types 5-HT2A antagonists Antagonists of the 5-HT2A, 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, 5-HT1 receptor blocker. It causes retroperitoneal fibrosis and mediastinal fibrosis. * Quetiapine blocks 5-HT2A, 5-HT1A, 5-HT1A, dopamine receptors DRD1, D1 and DRD2, D2, histamine receptor HRH1, H1, and A1 adrenoreceptors. 5-HT2A/2C antagonists * Ketanserin Antihypertensive. Blocks 5-HT2A, 5-HT2C, 5-HT2C and Alpha 1 adrenoreceptor, Alpha 1 (A1) adrenoreceptors. * Risperidone antipsychotic * Trazodone * Nefazodone 5-HT3 antagonists Another s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
DRD2
Dopamine receptor D2, also known as D2R, is a protein that, in humans, is encoded by the ''DRD2'' gene. After work from Paul Greengard's lab had suggested that dopamine receptors were the site of action of antipsychotic drugs, several groups, including those of Solomon H. Snyder and Philip Seeman used a radiolabeled antipsychotic drug to identify what is now known as the dopamine D2 receptor. The dopamine D2 receptor is the main receptor for most antipsychotic drugs. The structure of DRD2 in complex with the atypical antipsychotic risperidone has been determined. Function D2 receptors are coupled to Gi subtype of G protein. This G protein-coupled receptor inhibits adenylyl cyclase activity. In mice, regulation of D2R surface expression by the neuronal calcium sensor-1 (NCS-1) in the dentate gyrus is involved in exploration, synaptic plasticity and memory formation. Studies have shown potential roles for D2R in retrieval of fear memories in the prelimbic cortex and in di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postoperative Nausea And Vomiting
Postoperative nausea and vomiting (PONV) is the common complication of nausea, vomiting, or retching experienced by a person within the first 24 hours following a surgical procedure. Untreated, PONV affects about 30% of people undergoing general anesthesia each year, with rates rising to 70–80% among those considered high-risk. Postoperative nausea and vomiting can be highly distressing for people undergoing surgery and may pose significant barriers towards recovery, cause surgical complications, and result in delayed discharge from the surgical center if not managed properly. Cause Risk factors Risk factors for PONV can be classified into three main categories: patient-related, surgical, and anesthetic-related. Patient-related Patient factors that confer increased risk for PONV include female gender, younger age (<16 years old), , non-smoking status, high le ... [...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 debilitating 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 T ... [...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 ... [...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 receptor, G protein-coupled receptors. This ion channel is cation-selective and mediates neuronal depolarization and excitation within the Central nervous system, central and Peripheral nervous system, 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 perme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nefazodone
Nefazodone, sold formerly under the brand names Serzone, Dutonin, and Nefadar among others, is an atypical antidepressant medication which is used in the treatment of depression and for other uses. Nefazodone was withdrawn in most countries by 2004 (due to liver toxicity), but was, as of December 2021, still available in the United States. The medication is taken by mouth. Side effects of nefazodone include dry mouth, sleepiness, nausea, dizziness, blurred vision, weakness, lightheadedness, confusion, and postural low blood pressure, among others. Rarely, nefazodone can cause serious liver damage, with an incidence of death or liver transplantation of about 1 in every 250,000 to 300,000 patient years. Nefazodone is a phenylpiperazine compound and is related to trazodone. It has been described as a serotonin antagonist and reuptake inhibitor (SARI) due to its combined actions as a potent antagonist of the serotonin 5-HT2A and 5-HT2C receptors and weak serotonin–norep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trazodone
Trazodone is an antidepressant medication used to treat major depressive disorder, anxiety disorders, and insomnia. It is a phenylpiperazine compound of the serotonin antagonist and reuptake inhibitor (SARI) class. 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. 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 2022, it was the eighteenth most commonly prescribed medication in the United States, with more than 27million 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 trials suggest that the antidepressant eff ... [...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, as well as aggressive and self-injurious behaviors associated with autism spectrum disorder. It is taken either by mouth or by injection (i.e., subcutaneous or intramuscular). The injectable versions are long-acting and last for 2–4 weeks. Common side effects include weight gain, drowsiness, fatigue, insomnia, dry mouth, constipation, elevated prolactin levels, and restlessness. Serious side effects may include the potentially permanent movement disorder tardive dyskinesia, as well as neuroleptic malignant syndrome, an increased risk of suicide, and 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 and ser ... [...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 diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha 1 Adrenoreceptor
alpha-1 (α1) adrenergic are G protein-coupled receptors (GPCRs) associated with the Gq heterotrimeric G protein. α1-adrenergic receptors are subdivided into three highly homologous subtypes, i.e., α1A-, α1B-, and α1D-adrenergic receptor subtypes. There is no α1C receptor. At one time, there was a subtype known as α1C, but it was found to be identical to the previously discovered α1A receptor subtype. To avoid confusion, naming was continued with the letter D. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α1-adrenergic receptors in the central and peripheral nervous systems. The crystal structure of the α1B-adrenergic receptor subtype has been determined in complex with the inverse agonist (+)-cyclazosin. Effects The α1-adrenergic receptor has several general functions in common with the α2-adrenergic receptor, but also has specific effects of its own. α1-receptors primarily mediate smooth muscle contraction, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT2C
The 5-HT2C receptor is a subtype of the 5-HT2 receptor that binds the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). Like all 5-HT2 receptors, it is a G protein-coupled receptor (GPCR) that is coupled to Gq/G11 and mediates excitatory neurotransmission. ''HTR2C'' denotes the human gene encoding for the receptor, that in humans is located on the X chromosome. As males have one copy of the gene and females have one of the two copies of the gene repressed, polymorphisms at this receptor can affect the two sexes to differing extent. Structure At the cell surface the receptor exists as a homodimer. The crystal structure has been known since 2018. Distribution 5-HT2C receptors are located mainly in the choroid plexus, and in rats is also found in many other brain regions in high concentrations, including parts of the hippocampus, anterior olfactory nucleus, substantia nigra, several brainstem nuclei, amygdala, subthalamic nucleus and Habenula#Lateral habenula, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
