Present-day uses of niacin: effects on lipid and non-lipid parameters

Existing guidelines for the prevention and treatment of coronary artery disease focus on lowering low-density lipoprotein cholesterol (LDL-C) as the primary lipid target. However, there has been increasing interest in raising high-density lipoprotein cholesterol (HDL-C) due to strong evidence linking low HDL-C levels with an increased risk of atherosclerosis. Raising HDL-C levels with lifestyle changes and pharmacologic interventions appear to reduce the risk of coronary artery disease beyond that of lowering LDL-C alone. Niacin has a substantial HDL-C raising effect, and also may beneficially alter total cholesterol, LDL-C and triglyceride levels. Niacin also exhibits antioxidant, anti-inflammatory and other beneficial effects on atherosclerosis. Niacin is safe and effective to use in women, in patients with diabetes mellitus and/or metabolic syndrome, and when used in combination with statins. Niacin has the promise of being a powerful pharmacologic agent in the fight against atherosclerotic disease, although additional clinical studies are required to examine this further.     

高效液相色谱法测定肌醇烟酸脂及其制剂的有关物质

目的建立高效液相色谱法测定肌醇烟酸脂的有关物质。方法色谱柱为Diamonsil-C18,流动相为水-甲醇-四氢呋喃(45:45:10),检测波长262nm,流速1.0mL/min,进样量10μL。采用自身对照法。结果最大杂质峰不超过对照溶液主峰,其杂质峰面积之和不超过对照溶液主峰。结论本方法能灵敏、准确、可靠的进行杂质检测,对肌醇烟酸脂有关物质的控制有一定意义。     

洛伐他汀烟酸缓释片的释放度研究

目的　比较自制洛伐他汀烟酸缓释片与国外制剂ALTOCOR的药物释放情况。方法　转篮法。首先以0 .5 %十二烷基硫酸钠的磷酸二氢钠溶液(pH7.0 ) 90 0mL为介质,4 5min后更换溶出介质为水90 0mL。洛伐他汀采用高效液相法测定,烟酸采用紫外分光光度法测定。结果　自制片和国外制剂ALTOCOR中洛伐他汀在4 5min内的溶出度均大于75 % ,烟酸的释放曲线均符合Higuchi方程,其相关系数分别为0 .996 8和0 .996 9。结论　自制片与国外制剂ALTOCOR中烟酸的释放曲线相似因子f2 值为99.95 ,非常相似。     

他汀联合烟酸类药物的临床试验评价

在他汀治疗使低密度脂蛋白胆固醇(LDL-C)达标的后,对高密度脂蛋白胆固醇(HDL-C)降低的患者加用烟酸,可以升高HDL-C并降低甘油三酯,显著改善血脂谱。尽管小规模临床试验显示在他汀基础上联合烟酸可以延缓冠状动脉斑块或颈动脉内膜中层厚度的进展,但他汀联合烟酸的疗效至今仍然没有在大规模临床试验中得到证实。单纯升高HDL-C血浆水平而不关注HDL-C的清除是目前针对HDL-C干预治疗的问题所在,他汀联合烟酸的有效性和安全性有待于进一步证实。     

烟酸缓释片的研制及其释药特性的研究

目的:制备烟酸缓释片,并对其释药性质进行了研究.方法:分别采用不同粒度烟酸和不同粒度、粘度、含量的羟丙甲纤维素以及不同压力的方法制备烟酸缓释片,在不同pH值释放介质中测定其释放度,并与国外同类缓释片进行比较.结果:HPMC的粒度、粘度、压片压力对本制剂的释药影响不大.随着烟酸粒度的减小,HPMC用量的增加和释放介质的pH值增高,释药速率减慢.结论:烟酸缓释片的释药过程符合Higuchi方程,影响药物释放的主要因素是烟酸的粒度、HPMC的用量和释放介质的pH值;研制的烟酸缓释片与国外样品体外释放速率相近.     

The comparative bioavailability of an extended-release niacin and lovastatin fixed dose combination tablet versus extended-release niacin tablet, lovastatin tablet and a combination of extended-release niacin tablet and lovastatin tablet

Lovastatin and extended-release (ER) niacin in a fixed dose combination (Advicor) is approved for the treatment of dyslipidemia. Since both drugs are extensively metabolized, this study investigated the bioavailability and pharmacokinetics of their co-administration following single-dose administration. In a 4-way crossover study 40 subjects received: two 1000/20 Advicor tablets (ADV), two 1000 mg niacin ER tablets (NSP), two 20mg lovastatin tablets (Mevacor; MEV), and two niacin ER 1000 mg tablets with two lovastatin 20mg tablets (NSP+MEV). Plasma was assayed for niacin, nicotinuric acid (NUA), lovastatin, lovastatin acid and HMGCoA reductase inhibition. Urine was assayed for niacin and its metabolites, NUA, N-methylnicotinamide and N-methyl-2pyridone-5-carboxamide. Least square mean ratios and 90% confidence intervals for C(max) and AUC((0-t)) were determined for NSP+MEV versus MEV or NSP, ADV versus MEV or NSP, and ADV versus NSP+MEV. Co-administration of niacin and lovastatin did not significantly influence C(max) and AUC((0-t)) of lovastatin, niacin, NUA and total urinary recovery of niacin and metabolites. A 22 to 25% decrease in lovastatin acid C(max) was observed while lovastatin acid AUC((0-t)) was not affected. The HMGCoA reductase inhibition C(max) and AUC((0-t)) were not affected indicating that the difference in lovastatin acid C(max) was not clinically relevant.     

Safety and tolerability of extended-release niacin with laropiprant

Introduction: Niacin is one of the oldest drugs used in the treatment of dyslipidemia. Previously its use has been limited because of excessive flushing. Now an agent laropiprant (LRP) has been developed, which blocks the flushing pathway. Therefore, it is time to collate available information to assess the safety and tolerability of combining niacin with LRP.

Areas covered: The authors searched PubMed and MEDLINE for literature published between January 2006 and July 2011, for safety and tolerability reports of extended-release niacin (ERN) with LRP.

Expert opinion: The addition of LRP to ERN, by reducing the side effect ‘flushing’, may enable lipidologists and physicians to use niacin more widely as part of lipid modification therapy, especially since the combination can be safely added to statins. However, it has to be accepted that the addition of LRP does not completely abolish flushing. The favorable safety profile supports the use of LRP to achieve higher therapeutic dosing of niacin.     

评价烟酸缓释片治疗混合性高脂血症的疗效及安全性

目的探讨烟酸缓释片治疗混合性高脂血症的临床疗效及安全性。方法85例高脂血症患者,随机分为阿伐他汀组(n=42,10 mg·d-1)和烟酸缓释片组(n=43,500 mg·d-1),疗程均为4 wk,观察治疗前后主要血脂参数(TC、TC、LDL-C、HDL- C、α-脂蛋白)的变化率、达标率及不良反应。结果在降低TG、α-脂蛋白,升高HDL-C方面,烟酸缓释片优于他汀类药物。在不良反应和安全性方面,烟酸缓释片组有较高比例患者出现皮肤潮红和瘙痒,但对肝、肾功能影响无统计学意义。结论烟酸缓释片(500 mg·d-1)可以更全面地改善混合性高脂血症患者的血脂异常,尤其是升高HDL-C、降低TG和α-脂蛋白方面,安全性好,但其耐受性和依从性方面较阿伐他汀差。     

Combination lipid therapy in type 2 diabetes mellitus

Introduction: A significant drop in cardiovascular risk has been seen in patients with type 2 diabetes treated with statins. However, this cardiovascular risk remains high, compared with nondiabetic individuals. This is partly due to the typical abnormalities of diabetic dyslipidemia – hypertriglyceridemia and decreased high-density lipoprotein cholesterol (HDL-C) – that are uncontrolled by statins. For this reason, combination lipid therapy may be considered in patients with type 2 diabetes.

Areas covered: This review presents the main reasons for a combination lipid therapy in type 2 diabetes and the effects of several drugs, including fibrates, pioglitazone, niacin and omega 3, on diabetic dyslipidemia and the prevention of cardiovascular events. The real cardiovascular benefit of fibrates in patients with type 2 diabetes is not totally clear, but they may produce a significant benefit in patients with type 2 diabetes and diabetic dyslipidemia (hypertriglyceridemia, low HDL-C). Pioglitazone, which reduces triglycerides and increases HDL-C, has been shown to reduce the risk for major cardiovascular events in type 2 diabetes. Niacin and omega 3 fatty acids have a positive effect on diabetic dyslipidemia, but warrants clinical trials to demonstrate a clear cardiovascular benefit in type 2 diabetes.

Expert opinion: Although combination lipid therapy seems to be useful to control diabetic dyslipidemia, the efficacy of such combined therapies on significantly reducing cardiovascular risk has still to be confirmed by additional clinical trials.     

洛伐烟酸双层缓释片的制备及释放度考察

目的分别采用进口与国产羟丙基甲基纤维素 (HPMC)作为骨架材料制备洛伐烟酸缓释双层片 ,并比较国内外HPMC的缓释作用。方法用紫外分光光度法测定该制剂缓释层中烟酸的释放度 ,并用相似因子法和Chow′s法对溶出试验数据进行统计分析。结果使用国产HPMC制得的缓释片及进口HPMC制得的缓释片与国外市售片Niaspan的释放行为完全相似 ,相似因子分别为F2 =87 6和F2 =89 2 (5 0≤F2 ≤ 10 0 )。结论缓释片处方设计合理 ,工艺简单 ,用国产HPMC代替进口HPMC作为凝胶骨架材料完全可行     

Lipid and non-lipid effects of statins

Long- and short-term trials with the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have demonstrated significant reductions in cardiovascular events in patients with and without history of coronary heart disease. Statins are well-established low-density lipoprotein (LDL)-lowering agents, but their clinical benefit is believed to result from a number of lipid and non-lipid effects beyond LDL lowering, including a rise in plasma high-density lipoprotein levels. Beyond improving the lipid profile, statins have additional non-lipid effects including benefit on endothelial function, inflammatory mediators, intima-media thickening, prothombotic factors that ultimately result in plaque stabilization. These effects arise through the inhibition of several mevalonate-derived metabolites other than cholesterol itself, which are involved in the control of different cellular functions. Although statins represent the gold standard in the prevention and treatment of coronary heart disease, combination therapy with other lipid-lowering drugs, as well as novel therapeutic indications, may increase their therapeutic potential.     

A new paradigm for managing dyslipidemia with combination therapy: laropiprant + niacin + simvastatin

Importance of the field: Despite effective lowering of low-density lipoprotein cholesterol (LDL-C) with statin for prevention of cardiovascular adverse events, residual risk remains high due to low high-density lipoprotein cholesterol (HDL-C) levels in patients with mixed dyslipidemia. As a result, alternative treatment options to raise HDL-C are being investigated intensively. Currently, niacin is the most potent lipid lowering agent for raising HDL-C levels together with lowering of triglyceride and LDL-C. Previous clinical studies have demonstrated that niacin therapy significantly reduces the risk of cardiovascular events in high risk subjects. However, the clinical use of niacin is limited by its major adverse effect, cutaneous flushing. Although the use of extended-release (ER) formulation can reduce flushing, the tolerability and compliance of niacin remains suboptimal. A selective antagonist of prostaglandin D Type 1 receptor, laropiprant, has been investigated in a number of clinical studies and shown to be effective in reducing niacin-induced flushing. Despite the potential of laropiprant in reducing niacin-induced flushing, the long-term clinical efficacy and potential off-target side effects are not well studied.

Areas covered in this reviews: In this article, the pharmacological properties, clinical efficacy and future perspective of this combination therapy of simvastatin/ER niacin/laropiprant are reviewed.

What the reader will gain: Readers will understand both the mechanism and clinical effects of the combination therapy of simvastatin/ER niacin/laropiprant.

Take home message: The triple combination therapy of simvastatin/ER niacin/laropiprant may reduce flushing side effects and facilitate a more comprehensive treatment for patients with mixed dyslipidemia.     

洛伐他汀烟酸缓释片在比格犬体内的药代动力学

目的研究洛伐他汀烟酸缓释片在Beagle犬体内的药动学变化。方法6只Beagle犬采用两周期随机交叉实验设计,口服500mg洛伐他汀烟酸缓释片或烟酸片,采用反相高效液相色谱法(RP-HPLC)内标定量法测定烟酸血药浓度及药代动力学参数。结果Beagle犬口服给予洛伐他汀烟酸缓释片和烟酸片后,两者在犬体内的代谢均表现为一室模型,主要药动学参数:T12(Ke)64.99min vs.106.09min,T(peak)75.67min vs.112.20min,C(max)52.95μg.ml-1vs.28.50μg.ml-1,AUC 10831.10 vs.9086.42μg.ml-1。结论RP-HPLC内标定量测定烟酸,该方法操作简便、准确灵敏、重现性好,可用于烟酸在体内的药动学研究。单剂量口服洛伐他汀烟酸缓释片后测得的T12(Ke)、T(peak)和C(max)与烟酸组相比,差异性显著;AUC基本一致。缓释片的T12(Ke)、T(peak)明显长于烟酸片,Cmax低于烟酸片,这表明我们制备的复方洛伐他汀烟酸缓释片在Beagle犬体内具有缓释作用,相对生物利用度基本一致。     

Extended-release niacin with laropiprant: a review on efficacy,clinical effectiveness and safety

Mixed hyperlipidaemia is an important risk factor for the development of cardiovascular disease. The global management of mixed hyperlipidaemia is often more difficult than the treatment of pure hypercholesterolaemia in terms of goal attainments. Despite the significant clinical benefits provided by statins, many patients with mixed hyperlipidaemia do not achieve their recommended low-density and non-high-density lipoprotein cholesterol target goals with statin monotherapy. The combination of ezetimibe plus fenofibrate is a new alternative to improve the overall atherogenic lipid profile of patients with mixed hyperlipidaemia. However, the absence of comparative data with statin monotherapy and of long-term clinical studies suggests reservation of the combination of ezetimibe plus fenofibrate as a second-line therapy. Nevertheless, this combination therapy of ezetimibe plus fenofibrate seems particularly useful for patients with a poor response or intolerance to statin monotherapy.     

Safety assessment of niacin in the US Food and Drug Administration's mini‐sentinel system

Purpose

The Heart Protection Study 2—Treatment of HDL to Reduce the Incidence of Vascular Events (HPS2‐THRIVE) trial found higher incidence rates of adverse reactions, including bleeding, in patients receiving the combination of extended‐release niacin and laropiprant versus placebo. It is not known whether these adverse events are attributable to laropiprant, not approved in the USA, or to extended‐release niacin. We compared rates of major gastrointestinal bleeding and intracranial hemorrhage among initiators of extended‐release niacin and initiators of fenofibrate.

Methods

We used Mini‐Sentinel (now Sentinel) to conduct an observational, new user cohort analysis. We included data from 5 Data Partners covering the period from January 1, 2007 to August 31, 2013. Individuals who initiated extended‐release niacin were propensity score‐matched to individuals who initiated fenofibrate. Within the matched cohorts, we used Cox proportional hazards models to compare rates of hospitalization for major gastrointestinal bleeding events and intracranial hemorrhage assessed using validated claims‐based algorithms.

Results

A total of 234 242 eligible extended‐release niacin initiators were identified, of whom 210 389 (90%) were 1:1 propensity score‐matched to eligible fenofibrate initiators. In propensity score‐matched analyses, no differences were observed between exposure groups in rates of major gastrointestinal bleeding (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.82 to 1.18) or intracranial hemorrhage (HR, 1.21; 95% CI, 0.66 to 2.22). Results were similar in pre‐specified sensitivity and subgroup analyses.

Conclusions

We did not observe evidence for an association between extended‐release niacin versus fenofibrate and rates of major gastrointestinal bleeding or intracranial hemorrhage.     

Niacin extended-release/ lovastatin: combination therapy for lipid disorders

The new combination of niacin extended-release (ER) and lovastatin (Advicor?, Kos pharmaceuticals), is a powerful lipid modifying agent and takes advantage of the different mechanisms of action of its two components. Niacin decreases hepatic atherogenic apolipoprotein (apo) B production whereas lovastatin increases apoB removal. Whereas niacin potently increases high density lipoprotein (HDL) levels by decreasing hepatic removal of antiatherogenic apoA-I particles, 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase inhibitors (‘statins’) appear to increase production of apoA-I. Although there is no outcome data with this combination product, each component has been independently associated with a reduction of cardiovascular event risk by ～ 25 – 35%. The results of a long-term trial in 814 patients, where > 600 had been treated for 6 months and > 200 for 1 year, found reductions of 45 and 42% in low density lipoprotein cholesterol and triglycerides, respectively, at the maximum dose (niacin ER 2000 mg/ lovastatin 40 mg). HDL cholesterol increased by 41%. In addition, the combination decreased lipoprotein (a) by 25% and C-reactive protein by 24%. The niacin ER/lovastatin combination was generally well-tolerated. Flushing was the most common side effect, with ～ 10% of patients intolerant to niacin ER/lovastatin. Hepatotoxicity in this study was 0.5% and myopathy did not occur. Recent studies indicate that niacin can be used safely in diabetic patients who have good glucose control (HbA _1c < 9%). Once-daily niacin ER/lovastatin exhibits potent synergistic actions on multiple lipid risk factors and represents an effective new agent in the clinical management of dyslipidaemia. Outcome studies are needed to evaluate if combination therapy would result in additive effects on morbidity and mortality.     

RP-HPLC法测定Beagle犬血浆中烟酸浓度及烟酸药代动力学研究

目的:建立RP -HPLC法测定血浆中烟酸的药物浓度,并将建立的方法应用于Beagle犬测定烟酸缓释片的血药浓度,计算其药代动力学参数和相对生物利用度。方法:0 .1ml血浆样品经乙腈沉淀蛋白后直接进样;流动相为乙腈 水相(8 92 ) ,水相含10mmol·L-1磷酸二氢钾,用磷酸调pH值至4 .0 ,流速为1.0ml·min-1;色谱柱为汉邦科技LichrospherC18(5 μm,2 5 0mm×4 .6mmI .D .) ,检测波长为2 6 3nm。6只Beagle犬随机交叉口服5 0 0mg复方洛伐烟酸缓释片和5 0 0mg标准参比烟酸普通片后,用RP HPLC法测定血浆中烟酸的药物浓度。结果:分析方法符合生物样品分析要求。Beagle犬单剂量口服复方洛伐烟酸缓释片5 0 0mg后,估算的末端相t1 2 为1.3±1.2h ,Tmax为2 .3±0 .8h ,Cmax为35 .3±4 .9mg·L-1,MRT为3.5±0 .6h。复方洛伐烟酸缓释片的AUC、Cmax 明显低于烟酸普通片(P <0 .0 5 )。经配对t检验分析显示复方洛伐烟酸缓释片Tmax明显长于普通片(P <0 .0 5 )。结论:单剂量口服复方洛伐烟酸缓释片后,测得的Cmax和AUC与烟酸普通片均有显著性差异,受试缓释片的Tmax长于参比普通片,Cmax低于参比普通片,说明受试缓释片无突释现象,有一定的缓释效果。     

Laropiprant plus niacin for dyslipidemia and prevention of cardiovascular disease

Importance of the field: Prevention of cardiovascular disease has been only partially successful with the use of cholesterol-lowering drugs like statins. There is a residual risk remaining, which may be addressed by increasing protective high-density lipoprotein (HDL) cholesterol and apolipoprotein A1. The best drug available for that purpose is niacin. In addition to increasing HDL cholesterol and apolipoprotein A1, niacin decreases triglycerides, low-density lipoprotein (LDL)-cholesterol and lipoprotein(a) and has been named the broad-spectrum lipid drug.

Areas covered in this review: This review summarizes to what extent a new formulation of niacin may meet this request. The effects of niacin on lipoproteins, atherosclerosis and cardiovascular disease are described, from its first publication in 1955, and also its mechanism of action on lipoproteins and on flushing. The flushing inhibitor laropiprant is described as well as the antiflushing effect of this compound when added to extended-release niacin.

What the reader will gain: The reader will gain knowledge of the development of niacin as an antiatherosclerosis treatment and of the added value that laropiprant may offer this treatment principle; and also the present place of niacin/laropiprant in the armamentarium of cardiovascular preventive drugs.

Take home message: Niacin/laropiprant is a welcome means to address the residual risk in high-risk patients on statin therapy. However, the drug combination cannot completely eliminate niacin-induced side effects. Prescribing this treatment, therefore, will require careful provision of information and instruction to the patient.     

Effect of oxprenolol and metoprolol on serum lipid concentration

Summary The aim of the present study was to evaluate whether a reduction in HDL-cholesterol is peculiar to non cardioselective beta blockers or whether it is also produced by cardioselective beta₁-blockers. 16 patients with primary arterial hypertension on a balanced isocaloric diet were given oxprenolol 120 to 240 mg/day or metoprolol 100 to 200 mg/day in a random cross-over study. No significant change was observed after either treatment in fasting blood glucose, serum total cholesterol and triglycerides. HDL-cholesterol concentration was significantly decreased on metoprolol, from 41 to 36 mg/dl (p<0.05), while oxprenolol did not affect it at all. The difference might depend on intrinsic sympathomimetic activity which is possessed by oxprenolol and which metoprolol lacks.     

An update on the safety of nutraceuticals and effects on lipid parameters

Introduction: Cardiovascular diseases (CVDs) are the leading cause of mortality and disability in developed countries, whereas a large portion of patients in primary prevention have uncontrolled level of CVD risk factors. Dietary supplementation with bioactive natural compounds with demonstrated lipid-lowering effects is currently supported by the international guidelines for CVD prevention and some international expert panels.

Areas covered: This review provides insights on issues concerning the tolerability and safety of the most commonly used nutraceuticals with demonstrated lipid-lowering effect in humans. They will be then divided into three main categories according to their mechanism of action (cholesterol synthesis inhibitors, intestinal cholesterol absorption inhibitors, and LDL-C excretion stimulants) and their pharmacological profile will be discussed.

Expert opinion: A growing body of preclinical, epidemiological and clinical evidence has defined the tolerability and safety profile of the most commonly used lipid-lowering nutraceuticals. In the most part of cases, the side effects are mild and reversible. However, detailed knowledge of specific health risks and pharmacological interactions for each individual compound is needed for the management of frail patients, such as children, elderly, patients with liver or renal failure, and patients consuming numerous drugs.