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)

Dyslipidaemia may be treated with a number of safe and effective pharmacological agents that target specific lipid disorders through a variety of mechanisms. The bile-acid sequestrants--cholestyramine and colestipol--primarily decrease LDL cholesterol by binding bile acids, thereby decreasing intrahepatic cholesterol, and by increasing the activity of LDL receptors. Nicotinic acid lowers LDL cholesterol and triglyceride by decreasing VLDL synthesis and by decreasing free fatty acid mobilization from peripheral adipocytes. The HMG-CoA reductase inhibitors--fluvastatin, lovastatin, pravastatin and simvastatin--lower LDL cholesterol by partially inhibiting HMG-CoA reductase (the rate-limiting enzyme of cholesterol biosynthesis) and by increasing the activity of LDL receptors. The fibric-acid derivatives--bezafibrate, ciprofibrate, clofibrate, fenofibrate and gemfibrozil--primarily decrease triglyceride by increasing lipoprotein lipase activity and by decreasing the release of free fatty acids from peripheral adipose tissue. Probucol decreases LDL cholesterol by increasing non-receptor-mediated LDL clearance; as an anti-oxidant, probucol also decreases LDL oxidation; oxidized LDL which is thought to lead to atherogenesis. Although these agents have been proven safe in clinical trials, like any drug, they carry the risk for adverse effects. The bile-acid sequestrants may cause constipation, reflux oesophagitis, and dyspepsia, and may bind coadministered medications such as digitalis glycosides, beta blockers, warfarin, and exogenous thyroid hormone. Nicotinic acid use is commonly associated with flushing and pruritus and may also cause non-specific gastrointestinal complaints, hepatotoxicity (hepatic necrosis, hepatitis, or elevated liver enzymes), gout, myolysis, decreased glucose tolerance and increased fasting glucose levels, and ophthalmological complications including decreased visual acuity, toxic amblyopia, and cystic maculopathy. The HMG-CoA reductase inhibitors may produce liver enzyme elevations, creatine kinase elevations and rhabdomyolysis. The combination of a reductase inhibitor and a fibrate increases the risk for rhabdomyolysis. Possible adverse effects of the fibric-acid derivatives include abdominal discomfort, nausea, flatulence, increased lithogenicity of bile, liver enzyme elevations and creatine kinase elevations. Probucol may increase the QTc interval and may cause non-specific gastrointestinal complaints.
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PMID:Currently available hypolipidaemic drugs and future therapeutic developments. 859 27

Niacin has been used for many years to treat hyperlipidemia. It has been shown to reduce coronary death and non-fatal myocardial infarction and, in a separate analysis of long-term (15-year) follow-up, all cause mortality. It reduces total cholesterol, low density lipoprotein cholesterol (LDL-C) and triglycerides and increases high density lipoprotein cholesterol (HDL-C). Sustained-release niacin may be associated with more dramatic changes in LDL-C and triglyceride, whereas the short acting preparation causes greater increases in HDL-C. The increase of HDL-C occurs at a lower dose (1500 mg/day) than the reduction of LDL-C (> 1500 mg/day). Niacin also favorably influences other lipid parameters including lipoprotein(a) [Lp(a)], alimentary lipemia, familial defective apolipoprotein B-100 and small dense LDL. Combination of niacin with a bile acid sequestrant or a reductase inhibitor represents a powerful lipid-altering regimen. Whereas the reductase inhibitors and bile acid binding resins primarily affect LDL-C, the combined therapy has a synergistic effect to reduce LDL-C and, in addition, the niacin reduces triglycerides and increases HDL-C. The major drawback in the use of niacin is associated side effects (flushing and palpitations) and toxicity (worsening of diabetes control, exacerbation of peptic ulcer disease, gout, hepatitis). Niacin has a long history of use as a lipid lowering agent and has several attractive features. Unfortunately, the side effect profile of this agent warrants its use only in patients with marked dyslipidemia in whom side effects and potential toxicity are closely monitored.
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PMID:New developments in the use of niacin for treatment of hyperlipidemia: new considerations in the use of an old drug. 885 85

Niacin is the oldest and most versatile agent in use for the treatment of dyslipidemia. It has beneficial effects on low-density lipoprotein cholesterol; high-density lipoprotein cholesterol; the apolipoproteins B and A-I constituting these fractions; triglyceride; and lipoprotein(a). Together, these benefits lead to a diminished incidence of coronary artery disease among niacin users. The chief constraints against niacin use have been flushing, gastrointestinal discomfort, and metabolic effects including hepatotoxicity. Time-release niacin has been developed in part to limit flushing, and now a nighttime formulation (Niaspan) has been developed that assists in containing this untoward effect. In a pivotal metabolic study, bed-time administration of 1.5 g time-release niacin was shown to have the same beneficial effects as 1.5 g plain niacin in 3 divided doses and to be well tolerated. Previous studies suggest that bedtime niacin administration diminishes lipolysis and release of free fatty acids to the liver; this, in turn, leads to an abolition of the usual diurnal increase in plasma triglyceride, which may result in diminished formation and secretion of triglyceride in the very-low-density lipoprotein fraction.
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PMID:Clinical profiles of plain versus sustained-release niacin (Niaspan) and the physiologic rationale for nighttime dosing. 991 59

Immediate-release niacin manifests beneficial effects in cardiovascular disease with respect to dyslipidemic states. It lowers low-density lipoprotein (LDL) cholesterol, triglycerides, lipoprotein(a), and apoprotein B; at the same time, it increases high-density lipoprotein (HDL) cholesterol, HDL2, and apoprotein A-I. However, use of crystalline niacin has drawbacks: therapy requires multidose regimens, and side effects include flushing and pruritus. Slowing absorption with sustained-release formulations succeeds in decreasing flushing and increasing tolerance, but increases in hepatic enzyme levels have raised safety concerns. A new extended-release, once-daily formulation of niacin (Niaspan) shows promise in minimizing flushing while avoiding hepatotoxicity. A multicenter, randomized, double-blind clinical trial of Niaspan enrolled 122 patients with confirmed diagnosis of primary dyslipidemia (LDL cholesterol >4.14 mmol/L [160 mg/dL] and triglycerides <9 mmol/L [800 mg/dL]) into 3 treatment groups: (1) Niaspan 1,000 mg/day; (2) Niaspan 2,000 mg/day; and (3) placebo. The primary treatment endpoint was LDL-cholesterol level. This endpoint was not significantly affected by placebo (0.2% increase), but Niaspan decreased LDL cholesterol by 5.8% (1,000 mg/day) and 14.6% (2,000 mg/day) (p <0.001). Likewise, with placebo there were significant changes in total cholesterol, triglycerides, lipoprotein(a), and apoprotein B, whereas both Niaspan 1,000 and 2,000 mg/day significantly (p <0.001) decreased these parameters. In addition, both Niaspan groups showed significant (p <0.001) increases in HDL cholesterol (17% and 23%, respectively), including HDL subfractions. With respect to flushing, 20% of the placebo group reported at least 1 episode, whereas 88% and 83% of the Niaspon 1,000- and 2,000-mg/day groups, respectively, reported episodes. There was no hepatotoxicity as liver enzyme levels remained within clinically accepted limits in all treatment groups. However, Niaspan 2,000 mg/day showed a significant increase in aspartate aminotransferase compared with baseline and placebo. This trial demonstrated a cholesterol-modifying effect of Niaspan consistent with those reported for niacin, but demonstrated a better tolerance for flushing. Moreover, in contrast to sustained-release formulations, Niaspan showed relatively mild hepatic effects.
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PMID:A new extended-release niacin (Niaspan): efficacy, tolerability, and safety in hypercholesterolemic patients. 991 60

Usual risk factors for coronary artery disease account for only 25-50% of increased atherosclerotic risk in diabetes mellitus. Other obvious risk factors are hyperglycemia and dyslipidemia. However, hyperglycemia is a very late stage in the sequence of events from insulin resistance to frank diabetes, whereas lipoprotein abnormalities are manifested during the largely asymptomatic diabetic prodrome and contribute substantially to the increased risk of macrovascular disease. The insulin-resistant diabetes course affects virtually all lipids and lipoproteins. Chylomicron and very-low-density lipoprotein (VLDL) remnants accumulate, and triglycerides enrich high-density lipoprotein (HDL) and low-density lipoprotein (LDL), leading to high levels of potentially atherogenic particles and low levels of HDL cholesterol. Hyperglycemia eventually impairs removal of triglyceride-rich lipoproteins, the accumulation of which accentuates hypertriglyceridemia. As triglycerides increase-still within the so-called normal range-abnormalities in HDL and LDL became more apparent. Thus, when triglycerides are >200 mg/dL, LDL particles are small and dense (when they are <90 mg/dL, the particles are of the large, buoyant variety). The atherogenicity of small, dense LDL particles is attributed to their increased susceptibility to oxidation, but in many patients they may be a marker for insulin resistance or the presence of atherogenic VLDL. Hypertriglyceridemia is associated with atherosclerosis because (1) it is a marker for insulin resistance and atherogenic metabolic abnormalities; and (2) the small size of triglyceride-enriched lipoproteins enables them to infiltrate the blood vessel wall where they are oxidized, bind to receptors on macrophages, and ingested, leading to the development of the atherosclerotic lesion. Various studies (primary prevention with gemfibrozil: Helsinki Heart Study; secondary prevention with simvastatin and pravastatin: Scandinavian Simvastatin Survival Study [4S] and Cholesterol and Recurrent Events [CARE], respectively) have demonstrated that lipid-lowering therapy in type 2 diabetes is effective in decreasing the number of cardiac events. Risk reduction was 22% to 50% (statins) and approximately 65% (fibrate) relative to placebo. It was also noted (in 4S and CARE) that the risk of major coronary events in untreated diabetic patients was 1.5-1.7-fold greater than in untreated nondiabetic patients. Although gemfibrozil (fibric acid derivative) is more effective in decreasing triglycerides and increasing HDL cholesterol in diabetic patients than the statins, it does not change and may even increase LDL-cholesterol levels (fenofibrate may be an exception, decreasing LDL cholesterol by 20-25% in some studies). However, gemfibrozil does increase LDL particle size. Nevertheless, the statins are the current lipid-lowering drugs of choice because the change in LDL-cholesterol-to-HDL-cholesterol ratio is better than with gemfibrozil. Moreover, the diabetic patient may be more likely to benefit from statin therapy than the nondiabetic patient. It should be noted that, in theory, nicotinic acid can correct or improve all lipid or lipoprotein abnormalities in patients with type 2 diabetes. Unfortunately, it is relatively contraindicated because it causes insulin resistance and may precipitate or aggravate hyperglycemia (in addition to its other well-known side effects such as flushing, gastric irritation, development of hepatotoxicity, and hyperuricemia). It is unknown at present whether newer formulations such as once-daily Niaspan may be better tolerated in diabetes. In any case, most patients with type 2 diabetes have risk factors for coronary artery disease and qualify for aggressive LDL cholesterol-lowering therapy. At the same time, it is presently unknown whether improved glycemic control decreases coronary artery disease risk in such patients.
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PMID:Diabetic dyslipidemia. 991 65

Combination therapy is increasingly recommended for patients with multiple lipid disorders, especially those at high risk for coronary events. We investigated the long-term safety and effectiveness of a new drug formulation containing once-daily extended-release niacin and lovastatin. A total of 814 men and women (mean age 59 years) with dyslipidemia were enrolled in a 52-week multicenter, open-label study. We used 4 escalating doses (niacin/lovastatin in milligrams): 500/10 for the first month, 1,000/20 for the second, 1,500/30 for the third, and 2,000/40 for the fourth month through week 52. Dose-dependent effects were observed for all major lipid parameters. At week 16, mean low-density lipoprotein (LDL) cholesterol and triglycerides were reduced by 47% and 41%, respectively; mean high-density lipoprotein (HDL) cholesterol was increased by 30% (all p <0.001). LDL/HDL cholesterol and total/HDL cholesterol ratios were also decreased by 58% and 48%, respectively. These effects persisted through week 52, except for the mean increase in HDL cholesterol, which had increased to 41% at 1 year. Lipoprotein (a) and C-reactive protein also decreased in a dose-related manner (by 25% and 24%, respectively, on 2,000/40 mg; p <0.01 vs baseline). Treatment was generally well tolerated. The most common adverse event was flushing, which caused 10% of patients to withdraw. Other adverse events included gastrointestinal upset, pruritus, rash, and headache. Drug-induced myopathy did not occur in any patient. The incidence of elevated liver enzymes to >3 times the upper limit of normal was 0.5%. Once-daily niacin/lovastatin exhibits substantial effects on multiple lipid risk factors and represents a significant new treatment option in the management of dyslipidemia.
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PMID:Long-term safety and efficacy of a once-daily niacin/lovastatin formulation for patients with dyslipidemia. 1189 8

Advicor (lovastatin and extended-release niacin) is the first cholesterol-lowering combination product to become available for the management of hyperlipidemia. Lovastatin significantly lowers low-density lipoprotein cholesterol, whereas niacin significantly lowers triglycerides and lipoprotein (a) and markedly increases high-density lipoprotein cholesterol. These effects are ideal for managing a variety of lipid disorders, including metabolic syndrome. Lovastatin and niacin reduce coronary heart disease mortality in primary and secondary prevention patients, respectively. The extended-release niacin component uses a unique technology to minimize adverse effects (e.g., flushing and hepatotoxicity) while retaining the same lipid-altering effects as immediate-release niacin. The combination product appears to be well tolerated, with discontinuation due to adverse effects other than flushing occurring in a similar percent of patients as for lovastatin in clinical trials. Approximately 9% of patients discontinued the combination product due to flush. No confined cases of myopathy or hepatotoxicity have been reported with this product. Once-daily dosing provides ease of administration that should improve compliance and result in a greater proportion of patients meeting their low-density lipoprotein cholesterol goals. The nomenclature surrounding niacin products used to treat dyslipidemias is confusing. While only two types of niacin formulations exist (immediate-release formulations and formulations which dissolve more slowly than immediate-release formulations), government regulations allow for slowly dissolved niacin formulations to be divided into two types of niacin products; those that are available over-the-counter (OTC) and those that are available by prescription only. Over-the-counter slowly dissolved niacin preparations are not classified as OTC per se, but are considered "nutritional supplements". For this reason, they fall under the jurisdiction of the Federal Trade Commission and do not fall under the umbrella of the FDA branch that controls dyslipidemic products (Endocrine and Metabolic Division of the Center for Drug Evaluation and Research). The slowly dissolved niacin nutritional supplements have not been reviewed by the FDA for safety nor efficacy in the treatment of dyslipidemia nor are they required to meet generic drug rules (even though various brands are available). These brands are described on their labels as "sustained-release", "timed-release", and "slow-release" for example. Only two slowly absorbed niacin products have been approved by the FDA for the treatment of dyslipidemia; they are Niaspan (Kos Pharmaceuticals, Inc., Miami, FL) and Advicor (Kos Pharmaceuticals, Inc., Miami, FL). The term "extended-release" has been given to these two products to simplify the terminology and differentiate the products from immediate-release niacin. In this review, we will use "extended-release" to refer to the FDA approved slowly dissolving niacin preparation and "sustained-release" to refer to the nutritional supplements (not FDA approved).
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PMID:Lovastatin and extended-release niacin combination product: the first drug combination for the management of hyperlipidemia. 1197 44

The efficacy and safety profiles of various forms of niacin for treating dyslipidemia are described. Niacin is well recognized for treating dyslipidemia in adults and has been shown to be effective in reducing coronary events. It has a broad range of effects on serum lipids and lipoproteins, including lowering total cholesterol, low-density-lipoprotein (LDL) cholesterol, and triglycerides. Niacin is the most effective lipid-modifying drug for raising high-density-lipoprotein (HDL) cholesterol levels and has been shown to lower Lp(a) lipoprotein. Niacin reduces triglycerides and very-low-density-lipoprotein and LDL cholesterol synthesis, primarily by decreasing fatty acid mobilization from adipose tissue. Niacin appears to raise HDL cholesterol by reducing hepatic apolipoprotein A-l clearance and enhancing reverse cholesterol transport. Niacin is metabolized through a conjugation or nicotinamide pathway. Standard immediate-release niacin is metabolized primarily through the conjugation pathway, which results in a high frequency of flushing. Long-acting niacin is metabolized through the nicotinamide pathway, which results in less flushing but increases the risk of hepatotoxicity. Extended-release niacin has a more balanced metabolism and causes fewer of both types of adverse effects. Improved serum lipid levels during niacin therapy have been associated with clinical and angiographic evidence of reduced coronary artery disease, especially when combined with statins. Niacin is particularly useful for managing high triglyceride and low HDL cholesterol levels as well as the lipid abnormalities associated with metabolic syndrome, including those commonly encountered in patients with diabetes. Several niacin products are available with significant differences in their safety and efficacy profiles. Health care providers must consider the differences between agents when recommending niacin for dyslipidemia treatment.
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PMID:Niacin for dyslipidemia: considerations in product selection. 1278 70

The pharmacokinetics, efficacy, and safety of niacin and its various formulations are discussed. Niacin has been used for decades for the treatment of dyslipidemia because of its favorable effects on all lipoprotein parameters. Niacin significantly increases high-density lipoprotein cholesterol (HDL-C) more than any other available agent and reduces total cholesterol, low-density lipoprotein cholesterol (LDL-C), lipoprotein (a), and triglycerides. Niacin is currently available in immediate-release (IR), sustained-release (SR), and extended-release (ER) formulations that differ in their dissolution, pharmacokinetic, efficacy, and safety profiles. Important drawbacks to niacin therapy such as cutaneous flushing, associated with IR niacin, and hepatotoxicity, associated with SR niacin, have historically limited its use. The adverse effect profiles of the different niacin formulations can be explained by differences in their dissolution and absorption rates and metabolic disposition, which result in production of metabolites associated with the respective adverse effects. The ER niacin formulation, with an intermediate dissolution rate between the dissolution rates of IR and SR niacin, demonstrates reduced rates of cutaneous flushing compared with IR niacin and hepatotoxic effects compared with SR niacin. Pharmacists need to be familiar with the pharmacokinetics, efficacy, and safety of available niacin formulations so that they can optimally educate both patients and health care providers on the differences among niacin formulations, counsel on the proper selection of a niacin product, and provide strategies for improving tolerance and adherence to therapy.
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PMID:Overview of niacin formulations: differences in pharmacokinetics, efficacy, and safety. 1290 Oct 25

Niacin extended-release/lovastatin is a new combination product approved for treatment of primary hypercholesterolemia and mixed dyslipidemia. This open-labeled, multicenter study evaluated the safety of bedtime niacin extended-release/lovastatin when dosed as initial therapy and patient compliance to treatment in various clinical practice settings. A total of 4,499 patients with dyslipidemia requiring drug intervention was enrolled at 1,081 sites. Patients were treated with 1 tablet (500 mg of niacin extended-release/20 mg of lovastatin) once nightly for 4 weeks and then 2 tablets for 8 weeks. Patients also received dietary counseling, educational materials, and reminders to call a toll-free number that provided further education about dyslipidemia and niacin extended-release/lovastatin. Primary end points were study compliance, increases in liver transaminases to >3 times the upper limit of normal, and clinical myopathy. Final study status was available for 4,217 patients (94%). Compliance to niacin extended-release/lovastatin was 77%, with 3,245 patients completing the study. Patients in the southeast and those enrolled by endocrinologists had the lowest compliance and highest adverse event rates. Flushing was the most common adverse event, reported by 18% of patients and leading to discontinuation by 6%. Incidence of increased aspartate aminotransferase and/or alanine aminotransferase >3 times the upper limit of normal was <0.3%. An increase of creatine phosphokinase to >5 times the upper limit of normal occurred in 0.24% of patients, and no cases of drug-induced myopathy were observed. Niacin extended-release/lovastatin 1,000/40 mg, dosed as initial therapy, was associated with good compliance and safety and had very low incidences of increased liver and muscle enzymes.
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PMID:Safety and compliance with once-daily niacin extended-release/lovastatin as initial therapy in the Impact of Medical Subspecialty on Patient Compliance to Treatment (IMPACT) study. 1527 93


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