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)

(1) For patients with hypercholesterolaemia requiring primary or secondary prevention, pravastatin, simvastatin and atorvastatin have a proven benefit in terms of mortality and/or morbidity. Gemfibrozil and cholestyramine have a proven impact on morbidity. (2) The lipid-lowering properties of immediate-release nicotinic acid have been known for about 50 years, as have its frequent and sometimes severe adverse effects. About 70% of patients experience cutaneous flushing, and 20-30% develop gastrointestinal adverse effects. Hepatotoxic effects occur in about 2% of patients, especially in those using high daily doses or sustained-release formulations. (3) The clinical evaluation of immediate-release nicotinic acid is mainly based on two comparative placebo-controlled trials. One, involving 5000 patients monitored on average for 15 years, showed no effect on survival. One trial suggested that immediate-release nicotinic acid reduced the risk of recurrent myocardial infarction. (4) Sustained-release nicotinic acid has not been evaluated in terms of its effect on morbidity or mortality. It has been shown to lower LDL cholesterol and triglyceride levels and to raise the HDL cholesterol level. (5) This new pharmaceutical formulation has a profile and frequency of known adverse effects similar to those of immediate-release nicotinic acid. (6) When hypercholesterolaemia persists despite an appropriate diet, it is best to use one drug with a proven preventive impact on mortality and/or morbidity. This is not the case for sustained-release nicotinic acid. (7) When statin therapy is inadequate, it remains to be shown whether adding another cholesterol-lowering drug is beneficial in terms of morbidity and mortality. If, in rare cases, combination with a statin is envisaged, it is best to use gemfibrozil or cholestyramine. Note that gemfibrozil should only be combined with a statin with the greatest caution.
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PMID:Nicotinic acid: new/old drug. Immediate or sustained release: too risky for a drug with no proven benefit. 1716 43

Half a century ago, nicotinic acid (niacin) was introduced into the clinic as the first orally available drug to treat high cholesterol levels and to improve the balance between (V)low density lipoproteins (LDL) and high density lipoproteins (HDL). Remarkably, its putative mechanism of action has only been recently elucidated, particularly because of the cloning of a G protein-coupled receptor (HM74A or GPR109A). This receptor responds to both nicotinic acid and the ketone body beta-hydroxybutyrate, the latter thought to be the more probable endogenous ligand for HM74A. In this review, we will discuss the pharmacology and medicinal chemistry of this receptor subtype and a related one (HM74 or GPR109B). Although still in its infancy, the ligand repertoire is developing, and a number of compound classes have now been described, among which are both full and partial agonists. Antagonists, however, are still lacking, thus compromising thorough pharmacological studies. Mutagenesis experiments have provided clues regarding the ligand binding site; in particular, an arginine residue in transmembrane domain 3 of the receptor seems to recognize the acidic moiety present in nicotinic acid and related substances. HM74A has also been linked to one of the major side effects of nicotinic acid, that is, flushing, since this receptor subtype also occurs in skin immune cells. It is not known yet whether HM74 is also present on these cells. Since nicotinic acid is one of the few available medicines that raise HDL ("good cholesterol") levels, HM74A and HM74 appear promising targets for future pharmacotherapy.
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PMID:Nicotinic acid receptor subtypes and their ligands. 1723 56

Niacin (nicotinic acid) reduces cardiovascular events in patients with dyslipidemia. However, symptoms associated with niacin-induced vasodilation (e.g., flushing) have limited its use. Laropiprant is a selective antagonist of the prostaglandin D(2) receptor subtype 1 (DP1), which may mediate niacin-induced vasodilation. The aim of this proof-of-concept study was to evaluate the effects of laropiprant (vs placebo) on niacin-induced cutaneous vasodilation. Coadministration of laropiprant 30, 100, and 300 mg with extended-release (ER) niacin significantly lowered flushing symptom scores (by approximately 50% or more) and also significantly reduced malar skin blood flow measured by laser Doppler perfusion imaging. Laropiprant was effective after multiple doses in reducing symptoms of flushing and attenuating the increased malar skin blood flow induced by ER niacin. In conclusion, the DP1 receptor antagonist laropiprant was effective in suppressing both subjective and objective manifestations of niacin-induced vasodilation.
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PMID:Suppression of niacin-induced vasodilation with an antagonist to prostaglandin D2 receptor subtype 1. 1739 21

In addition to its use as a nutritional supplement, niacin (nicotinic acid or vitamin B3) is medically prescribed to treat hyperlipidemia and hypercholesterolemia. Use of niacin in low doses usually leads to few adverse drug reactions (ADRs); however, at larger doses, niacin can cause skin flushing, itching, and occasionally more serious effects. The 2005 annual report of the American Association of Poison Control Centers documented 3,109 reports of exposures to niacin. During 2006, the Rocky Mountain Poison and Drug Center (RMPDC) in Denver, Colorado, received multiple calls regarding ADRs after nonmedical use of niacin. A review of call records indicated various uses of niacin, including attempts to alter or mask results of urine drug tests, although no scientific evidence exists that ingestion of niacin can alter a drug test result. To determine the extent of niacin use in attempts to alter drug test results, reports to RMPDC of niacin ADRs were reviewed for the period January--September 2006. The results identified 18 persons who reported nonsuicidal, intentional, nonmedical reasons for using niacin, including eight who specified altering drug test results as their reason for using niacin. Ten other persons, among an additional 18 who offered no reason for niacin use, were categorized as possible users of niacin to try to alter drug test results because of their ages or the amount of niacin ingested. Clinicians, especially those whose patients include teens and young adults, should be aware of the potential use of niacin in attempts to defeat urine drug tests.
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PMID:Use of niacin in attempts to defeat urine drug testing--five states, January-September 2006. 1744 21

Nicotinic acid remains the most effective therapeutic agent for the treatment and prevention of atherosclerosis resulting from low high density lipoprotein cholesterol. The therapeutic actions of nicotinic acid are mediated by GPR109A, a Gi protein-coupled receptor, expressed primarily on adipocytes, Langerhans cells, and macrophage. Unfortunately, a severe, cutaneous flushing side effect limits its use and patient compliance. The mechanism of high density lipoprotein elevation is not clearly established but assumed to be influenced by an inhibition of lipolysis in the adipose. The flushing side effect appears to be mediated by the release of prostaglandin D2 from Langerhans cells in the skin. We hypothesized that the signal transduction pathways mediating the anti-lipolytic and prostaglandin D2/flushing pathways are distinct and that agonists may be identified that are capable of selectively eliciting the therapeutic, anti-lipolytic pathway while avoiding the activation of the parallel flush-inducing pathway. We have identified a number of GPR109A pyrazole agonists that are capable of fully inhibiting lipolysis in vitro and in vivo and not only fail to elicit a flushing response but can antagonize the ability of nicotinic acid to elicit a flush response in vivo. In contrast to flushing agonists, exposure of cells expressing GPR109A to the non-flushing agonists fails to induce internalization of the receptor or to activate ERK 1/2 mitogen-activated protein kinase phosphorylation.
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PMID:Nicotinic acid receptor agonists differentially activate downstream effectors. 1745 18

Niacin (nicotinic acid and nicotinamide) is a vitamin used as a source of the NAD+ and NADP+ coenzymes required for many metabolic processes. Its low dietary levels induce the development of pellagra. Niacin has been used for decades in the treatment of patients with disturbed lipid and lipoprotein metabolism, this being the main cause of atherosclerotic changes in cardiovascular diseases. It is still the most efficacious drug in terms of its ability to increase HDL cholesterol content accompanied by a decrease in all atherogenic lipoproteins (VLDL, LDL, and L(a)) as well as fatty acids and triglycerides. Niacin also increases adiponectin level, which might result in additional atheroprotection. There are studies confirming the beneficial action of niacin against migraine and hyperphosphatemia associated with renal failure, ethanol-induced neurodegeneration, and loss of beta-cell function in type 1 diabetes. Moreover, it augments plasma tryptophan concentrations in HIV-infected patients and thyroid radiosensitivity to 131I. Inhibition of the invasion of hepatoma cells has also been proven. However, it is necessary to point out that the currently applied niacin preparations might exhibit such side effects as cutaneous flushing, gastrointestinal disturbances, and hepatotoxicity, particularly during treatment with sustained-release niacin preparations. The recent discovery of the G-protein-coupled receptor GPR109A, which mediates the antilipolytic effects induced by nicotinic acid in adipocytes as well as cutaneous vasodilation, allows the development of new agents interacting with this receptor. In view of these observations, niacin therapy must be accompanied by control of the choice of niacin preparation and its dose in order to eliminate or at least limit its side effects.
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PMID:[Niacin in therapy]. 1755 32

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

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


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