Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Niacin (nicotinic acid) favorably affects multiple serum lipid parameters that are believed to be cardiovascular risk factors, but is also associated with a cutaneous flushing adverse effect. The recent discovery of a G-protein-coupled receptor target for niacin (termed GPR109alpha) has stimulated interest in the discovery of new compounds with niacin-like effects on lipids, but with fewer adverse effects. This review discusses the progress made toward the discovery of such molecules and highlights the pharmacological models used to enable their identification. The advances made in both these areas may help to determine whether GPR109alpha is the molecular target responsible for the beneficial anti-atherogenic effects of niacin.
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PMID:Recent progress in the discovery of niacin receptor agonists. 1765 87

Pharmacological doses of nicotinic acid induce a profound change in the plasma levels of various lipids and lipoproteins. The ability of nicotinic acid to strongly increase the plasma concentration of high-density lipoprotein (HDL) cholesterol has in recent years led to an increased interest in the pharmacological potential of nicotinic acid. There is increasing evidence that nicotinic acid alone or in addition to LDL cholesterol-lowering drugs can reduce the progression of atherosclerosis and reduce the risk of cardiovascular events. The clinical use of nicotinic acid is, however, hindered by harmless but unpleasant side effects, especially by a strong cutaneous vasodilation called flushing. The recent discovery of the G protein-coupled receptor GPR109A (HM74A or PUMA-G) as a receptor for nicotinic acid has allowed for better understanding of the mechanisms underlying the metabolic and vascular effects of nicotinic acid. On the basis of recent progress in understanding the pharmacological effects of nicotinic acid, new strategies are in development to better exploit the pharmacological potential of nicotinic acid. New drugs acting via the nicotinic acid receptor or related receptors, as well as new co-medications that suppress unwanted effects of nicotinic acid, will most likely be introduced as new therapeutic options in the treatment of dyslipidemia and the prevention of cardiovascular diseases.
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PMID:Nicotinic acid: pharmacological effects and mechanisms of action. 1770 85

Low HDL-cholesterol (<1.02 mmol/L [40 mg/dL] in men or <1.29 mmol/L [50 mg/dL] in women) occurs in about one-third of European patients with dyslipidemia and is an independent cardiovascular risk factor. Simultaneous correction of low HDL-cholesterol and high total-cholesterol and LDL-cholesterol may provide reductions in cardiovascular morbidity and mortality beyond those possible with statins alone. Nicotinic acid (niacin in the US) is the most effective means of increasing HDL-cholesterol available and has been shown to reduce cardiovascular event rates significantly. Niaspan (prolonged-release nicotinic acid) provides a convenient, once-daily means of administering nicotinic acid. Clinical studies with Niaspan have demonstrated marked, long-term increases in HDL-cholesterol with additional useful benefits on triglycerides, LDL-cholesterol, and lipid sub-profiles. The NAUTILUS study demonstrated the beneficial efficacy and tolerability profiles of Niaspan in a usual-care setting. The most common side-effect of Niaspan is flushing, which infrequently causes treatment discontinuation and which usually subsides over continued treatment. The ARBITER 2 and ARBITER 3 studies showed 1-2 years of treatment with Niaspan plus a statin induced regression of atherosclerosis in patients with coronary artery disease. The effect of Niaspan-statin treatment, relative to a statin alone, on clinical cardiovascular outcomes is currently under evaluation. Niaspan represents a practical means of correcting low HDL-cholesterol, an independent risk factor for adverse cardiovascular outcomes.
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PMID:Prolonged-release nicotinic acid for the management of dyslipidemia: an update including results from the NAUTILUS study. 1796 77

Prostaglandin D(2) (PGD(2)) is a cyclooxygenase (COX) product of arachidonic acid that activates D prostanoid receptors to modulate vascular, platelet, and leukocyte function in vitro. However, little is known about its enzymatic origin or its formation in vivo in cardiovascular or inflammatory disease. 11,15-dioxo-9alpha-hydroxy-2,3,4,5-tetranorprostan-1,20-dioic acid (tetranor PGDM) was identified by mass spectrometry as a metabolite of infused PGD(2) that is detectable in mouse and human urine. Using liquid chromatography-tandem mass spectrometry, tetranor PGDM was much more abundant than the PGD(2) metabolites, 11beta-PGF(2alpha) and 2,3-dinor-11beta-PGF(2alpha), in human urine and was the only endogenous metabolite detectable in mouse urine. Infusion of PGD(2) dose dependently increased urinary tetranor PGDM > 2,3-dinor-11beta-PGF(2alpha) > 11beta-PGF(2alpha) in mice. Deletion of either lipocalin-type or hemopoietic PGD synthase enzymes decreased urinary tetranor PGDM. Deletion or knockdown of COX-1, but not deletion of COX-2, decreased urinary tetranor PGDM in mice. Correspondingly, both PGDM and 2,3-dinor-11beta-PGF(2alpha) were suppressed by inhibition of COX-1 and COX-2, but not by selective inhibition of COX-2 in humans. PGD(2) has been implicated in both the development and resolution of inflammation. Administration of bacterial lipopolysaccharide coordinately elevated tetranor PGDM and 2,3-dinor-11beta-PGF(2alpha) in volunteers, coincident with a pyrexial and systemic inflammatory response, but both metabolites fell during the resolution phase. Niacin increased tetranor PGDM and 2,3-dinor-11beta-PGF(2alpha) in humans coincident with facial flushing. Tetranor PGDM is an abundant metabolite in urine that reflects modulated biosynthesis of PGD(2) in humans and mice.
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PMID:Tetranor PGDM, an abundant urinary metabolite reflects biosynthesis of prostaglandin D2 in mice and humans. 1799 63

Nicotinic acid has been in use as a lipid-lowering drug for five decades now. It is effective in lowering low-density lipoprotein (LDL)-cholesterol, triglycerides, and lipoprotein (a), and in increasing high-density lipoprotein (HDL)-cholesterol. All these effects are pronounced, and at present greater increase of HDL-cholesterol cannot be obtained by any other drug. Patients with hypertriglyceridaemia/low HDL-cholesterol are the most suitable candidates for being treated with this drug. This pattern is typical for type 2 diabetic patients, for patients with metabolic syndrome, and for those with impaired glucose tolerance. From a few studies, there is evidence that nicotinic acid is effective in reducing cardiovascular events. Although overall safety is good, the unpleasant side effect of flushing, albeit not harmful, precludes many patients from taking the drug. New formulations of intermediate release or a combination with anti-flush compounds should increase the compliance with the drug.
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PMID:Nicotinic acid in the treatment of hyperlipidaemia. 1800 12

Nicotinic acid has been used for decades to treat dyslipidaemic states. In particular its ability to raise the plasma HDL cholesterol concentration has led to an increased interest in its pharmacological potential. The clinical use of nicotinic acid is somewhat limited due to several harmless but unpleasant side effects, most notably a cutaneous flushing phenomenon. With the recent discovery of a nicotinic acid receptor, it has become possible to better understand the mechanisms underlying the metabolic and vascular effects of nicotinic acid. Based on these new insights into the action of nicotinic acid, novel strategies are currently under development to maximize the pharmacological potential of this drug. The generation of both flush-reducing co-medications of nicotinic acid and novel drugs targeting the nicotinic acid receptor will provide future therapeutic options for the treatment of dyslipidaemic disorders.
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PMID:Nicotinic acid: an old drug with a promising future. 1803 24

Nicotinic acid (niacin) favorably affects very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and lipoprotein (a) (LP[a]) and increases high-density lipoprotein (HDL). Emerging data indicates vascular anti-inflammatory properties to additionally account for niacin's proven effects in cardiovascular disease. Recent evidence indicates that niacin acts on GPR109A and GPR109B (HM74A and HM74, respectively), receptors expressed in adipocytes and immune cells. In adipocytes, GPR109A activation reduces triglyceride (TG) lipolysis, resulting in decreased free fatty acid (FFA) mobilization to the liver. In humans, this mechanism has yet to be confirmed because the plasma FFA decrease is transient and is followed by a rebound increase in FFA levels. New evidence indicates niacin directly inhibits diacylglycerol acyltransferase 2 (DGAT2) isolated from human hepatocytes, resulting in accelerated hepatic apolipoprotein (apo)B degradation and decreased apoB secretion, thus explaining reductions in VLDL and LDL. This raises important questions as to whether stimulation of GPR109A in adipocytes or inhibition of DGAT2 in liver by niacin best explain the reduction in VLDL and LDL in dyslipidemic patients. Kinetic and in vitro studies indicate that niacin retards the hepatic catabolism of apoA-I but not liver scavenger receptor B1-mediated cholesterol esters, suggesting that niacin inhibits hepatic holoparticle HDL removal. Indeed, recent preliminary evidence suggests that niacin decreases surface expression of hepatic beta-chain of adenosine triphosphate synthase, which has been implicated in apoA-I/HDL holoparticle catabolism. GPR109A-mediated production of prostaglandin D2 in macrophages and Langerhan cells causes skin capillary vasodilation and explains, in part, niacin's effect on flushing. Development of niacin receptor agonists would, theoretically, result in adipocyte TG accumulation (and clinical adiposity) and increased flushing. This raises questions about niacin receptor agonists as therapeutic agents. Several niacin receptor agonists have been developed and patented, but their clinical effects have not been described. Future research is needed to determine whether niacin receptor agonists will demonstrate all the beneficial properties of nicotinic acid on atherosclerosis and without significant adverse effects.
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PMID:Nicotinic acid (niacin) receptor agonists: will they be useful therapeutic agents? 1804 54

Nicotinamide is the amide form of niacin and has anti-inflammatory properties that have led to its use in the treatment of several inflammatory dermatologic conditions, such as rosacea. Niacin has established its role in the prevention of coronary artery disease. Cutaneous flushing is a well-known and often dose-limiting side effect of niacin therapy, which does not occur with nicotinamide. We report a patient with rosacea who developed new onset flushing due to unauthorized substitution of niacin for nicotinamide. The anti-inflammatory mechanisms of nicotinamide and flushing mechanisms of niacin are discussed.
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PMID:Case reports: new onset flushing due to unauthorized substitution of niacin for nicotinamide. 1818 62

We previously reported familial aggregation in flush response to niacin skin patch among schizophrenia patients and their nonpsychotic relatives. However, little is known about whether this abnormal skin response is associated with genetic loading for schizophrenia. This study compared the niacin flush response in subjects from families with only one member affected with schizophrenia (simplex families) with those from families having a sib-pair with schizophrenia (multiplex families). Subjects were patients with schizophrenia and their nonpsychotic first-degree relatives from simplex families (176 probands, 260 parents, and 80 siblings) and multiplex families (311 probands, 180 parents, and 52 siblings) as well as 94 healthy controls. Niacin patches of 3 concentrations (0.001M, 0.01M, and 0.1M) were applied to forearm skin, and the flush response was rated at 5, 10, and 15 minutes, respectively, with a 4-point scale. More attenuated flush response to topical niacin was shown in schizophrenia probands and their relatives from multiplex families than in their counterparts from simplex families, and the differentiation was better revealed using 0.1M concentration of niacin than 0.01M or 0.001M. For the highest concentration of 0.1M and the longest time lag of 15 minutes, a subgroup of probands (23%), parents (27%), and siblings (19%) still exhibited nonflush response. Flush response to niacin skin patch is more impaired in schizophrenia patients and their relatives from families with higher genetic loading for schizophrenia, and this finding has implications for future genetic dissection of schizophrenia.
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PMID:Impaired flush response to niacin skin patch among schizophrenia patients and their nonpsychotic relatives: the effect of genetic loading. 1820 58

Niacin (nicotinic acid) is not optimally used mainly because of flushing, a process mediated primarily by prostaglandin D(2), which leads to poor patient compliance and suboptimal dosing. This phase II dose-ranging study was designed to assess whether the prostaglandin D(2) receptor 1 antagonist laropiprant (LRPT; MK-0524) would (1) reduce extended-release niacin (ERN)-induced flushing in dyslipidemic patients and (2) support a novel accelerated ERN dosing paradigm: initiating ERN at 1 g and advancing rapidly to 2 g. In part A of the study, 154 dyslipidemic patients were randomized to LRPT 150 mg/day or placebo in a 9-week, 2-period crossover study. Patients who completed part A (n = 122) entered part B (after a 2-week washout), together with additional patients who entered part B directly (n = 290). Part B patients were randomized to placebo, ERN 1 g (Niaspan, no previous titration), or ERN 1 g coadministered with LRPT 18.75, 37.5, 75, or 150 mg for 4 weeks, with doubling of the respective doses for the remaining 4 weeks. Patients treated with LRPT plus ERN experienced significantly less ERN-induced flushing than those treated with ERN alone during the initiation of treatment (ERN 1 g, week 1) and the maintenance treatment (ERN 1 to 2 g, weeks 2 to 8). All doses of LRPT were maximally effective in inhibiting niacin-induced flushing. LRPT did not alter the beneficial lipid effects of ERN. LRPT plus ERN was well tolerated. In conclusion, the significant reduction in ERN-induced flushing provided by LRPT plus ERN supports an accelerated ERN dose-advancement paradigm to achieve rapidly a 2-g dose in dyslipidemic patients.
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PMID:Effects of laropiprant on nicotinic acid-induced flushing in patients with dyslipidemia. 1830 10


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