Co-administration of ezetimibe and simvastatin in acute myocardial infarction

BACKGROUND: Recent trials in acute myocardial infarction indicate that intensive and early statin therapy that lowers low-density lipoprotein cholesterol (LDL-C) to < or = 70 mg dL(-1) is beneficial. The combination of statins with ezetimibe, a newly developed cholesterol-absorption inhibitor, can lead to a further reduction in LDL-C of up to 26%. In this study, we examined the rapidity and intensity of the lipid-lowering effect of ezetimibe co-administered with simvastatin immediately after myocardial infarction. MATERIALS AND METHODS: Sixty patients admitted for acute myocardial infarction were randomized to receive either simvastatin 40 mg (SIMVA), a combination of simvastatin 40 mg and ezetimibe 10 mg (EZE/SIMVA), or no lipid-lowering drugs (NLLD) and had their lipid levels assessed 2, 4 and 7 days later. RESULTS: At baseline, cardiovascular risk factors were similar in all three groups [mean (SD) LDL-C of 141 (36) mg dL(-1)]. At days 2 , 4 and 7 there was no significant change in mean LDL-C levels in the NLLD group (-10%, -6%, and -9%, all P > 0.09), while there were significant reductions with SIMVA (-15%, -27%, and -25%, respectively, all P < 0.001 vs. day 0) and even greater reductions with co-administration of EZE/SIMVA (-27%, -41%, and -51%, respectively, all P < 0.001 vs. day 0). The percentages of patients achieving LDL-C below 70 mg dL(-1) at days 4 and 7 were substantially greater with EZE/SIMVA (45% and 55%, respectively) than with SIMVA (5% and 10%, respectively), while no NLLD patient reached this goal. Triglyceride levels showed a progressive increase in the NLLD group (+45% at day 7, P < 0.05 vs. day 0), no change in the SIMVA group, but a decrease in the EZE/SIMVA group (-17% at day 7, P < 0.05 vs. day 0). No significant difference in HDL-C levels, tolerability, or clinical events was observed between the three groups. CONCLUSIONS: The co-administration of ezetimibe 10 mg with simvastatin 40 mg, by inhibiting cholesterol absorption and production, allowed more patients with acute myocardial infarction to reach LDL-C < or = 70 mg dL(-1) as early as the fourth day of treatment. The effects of such rapid and intense reduction in LDL-C on cardiovascular morbidity and mortality need to be evaluated in future clinical endpoint studies.     

依折麦布联合他汀类药物调血脂对主要心血管事件影响的系统评价

目的 系统评价依折麦布联合他汀类药物与单药应用双倍剂量他汀调血脂治疗中对主要心血管事件的影响。方法 检索CENTRAL、PubMed、EMBASE、中国生物医学文献数据库（CBM）、中国学术期刊全文数据库（CNKI）和万方等数据库,收集依折麦布联合他汀类药物与双倍剂量他汀类药物调脂治疗心血管不良事件的随机对照试验（RCT）,检索时限均从建库至2018年4月1日。由2名评价员独立筛选文献、提取资料并评价纳入研究的方法学质量,采用RevMan 5.3和R3.3.1软件进行数据分析。结果 共纳入16个RCTs,共3 534例患者。Meta-分析结果显示与单药应用双倍剂量他汀组相比,依折麦布联合他汀组可降低心绞痛［RR=0.36,95% CI（0.21,0.63）,P=0.000 3］、心肌梗死［RR=0.59,95% CI（0.36,0.95）,P=0.03］和主要心血管不良事件（心源性死亡、心绞痛、心肌梗死、血运重建）［RR=0.58,95% CI（0.38,0.87）,P=0.009］的发生风险,且具有统计学差异;两组血运重建、心源性死亡、卒中和全因死亡风险无统计学差异。结论 现有证据表明依折麦布联合他汀类药物比单药应用双倍剂量他汀能进一步降低不良心血管事件发生风险,但上述结果尚需更多多中心、大样本随机对照试验进一步证实。     

人血浆中依折麦布浓度测定方法的不确定度评定

目的研究高效液相色谱-串联质谱法(HPLC-MS/MS)法测定人血浆中依折麦布浓度的不确定度评定方法。方法对依折麦布浓度测定全过程进行分析,包括测定精密度、称量、标准溶液的配制、固相萃取过程、标准曲线拟合等进行分析评定,根据各分量计算出合成不确定度,由合成不确定度及其分布求得扩展不确定度。结果人血浆中依折麦布浓度为0.20、2.0、16 ng·m L-1,在置信概率为95%时的扩展不确定度分别为(0.213±0.082)、(2.07±0.15)、(16.1±1.11)ng·m L-1。结论测定中的不确定度主要来自标准曲线的拟合过程,评价方法适用于血浆中依折麦布测定的不确定度评定。     

UV and Three Derivative Spectrophotometric Methods for Determination of Ezetimibe in Tablet Formulation

UV, first, second and third derivative spectrophotometric methods have been developed for the determination of ezetimibe in pharmaceutical formulation. The solutions of standard and sample were prepared in methanol. For the first method, UV spectrophotometry, the quantitative determination of the drug was carried at 233 nm and the linearity range was found to be 6-16 μg/ml. For the first, second and third derivative spectrophotometric methods the drug was determined at 259.5 nm, 269 nm and 248 nm with the linearity ranges 4-14 μg/ml, 4-14 μg/ml and 4-16 μg/ml. The calibration graphs constructed at their wavelength of determination were found to be linear for UV and derivative spectrophotometric methods. All the proposed methods have been extensively validated. The described methods can be readily utilized for the analysis of pharmaceutical formulation. There was no significant difference between the performance of the proposed methods regarding the mean values and standard deviations.     

Pharmacodynamic interaction between the new selective cholesterol absorption inhibitor ezetimibe and simvastatin

AIMS: The primary aims of these two single-centre, randomized, evaluator-blind, placebo/positive-controlled, parallel-group studies were to evaluate the potential for pharmacodynamic and pharmacokinetic interaction between ezetimibe 0.25, 1, or 10 mg and simvastatin 10 mg (Study 1), and a pharmacodynamic interaction between ezetimibe 10 mg and simvastatin 20 mg (Study 2). Evaluation of the tolerance of the coadministration of ezetimibe and simvastatin was a secondary objective. METHODS: Eighty-two healthy men with low-density lipoprotein cholesterol (LDL-C) >or=130 mg dl-1 received study drug once daily in the morning for 14 days. In Study 1 (n=58), five groups of 11-12 subjects received simvastatin 10 mg alone, or with ezetimibe 0.25, 1, or 10 mg or placebo. In Study 2 (n=24), three groups of eight subjects received simvastatin 20 mg alone, ezetimibe 10 mg alone, or the combination. Blood samples were collected to measure serum lipids in both studies. Steady-state pharmacokinetics of simvastatin and its beta-hydroxy metabolite were evaluated in Study 1 only. RESULTS: In both studies, reported side-effects were generally mild, nonspecific, and similar among treatment groups. In Study 1, there were no indications of pharmacokinetic interactions between simvastatin and ezetimibe. All active treatments caused statistically significant (P<0.01) decreases in LDL-C concentration vs placebo from baseline to day 14. The coadministration of ezetimibe and simvastatin caused a dose-dependent reduction in LDL-C and total cholesterol, with no apparent effect on high-density lipoprotein cholesterol (HDL-C) or triglycerides. The coadministration of ezetimibe 10 mg and simvastatin 10 mg or 20 mg caused a statistically (P<0.01) greater percentage reduction (mean -17%, 95% CI -27.7, -6.2, and -18%, -28.4, -7.4, respectively) in LDL-C than simvastatin alone. CONCLUSIONS: The coadministration of ezetimibe at doses up to 10 mg with simvastatin 10 or 20 mg daily was well tolerated and caused a significant additive reduction in LDL-C compared with simvastatin alone. Additional clinical studies to assess the efficacy and safety of coadministration of ezetimibe and simvastatin are warranted.     

Combinations of ezetimibe with nonstatin drug regimens affecting lipid metabolism

In this article we discuss the available data on the effects of combined therapy of ezetimibe with agents affecting lipid metabolism other than statins. We consider studies evaluating the effects of combined therapy of ezetimibe with bile acid sequestrants, fenofibrate, niacin, n-3 fatty acids, plant sterols, orlistat, metformin, acarbose and glitazones. Combination of ezetimibe with bile acid sequestrants (especially colesevelam) was shown to have additional effects on lipid parameters in patients with hyperlipidemia. Combination of ezetimibe with fenofibrate may be a good approach to improve the overall lipid profile of patients with mixed hyperlipidemia. The addition of ezetimibe to niacin-based therapy can be useful for high-risk patients with dyslipidemia who are not achieving their assigned treatment goals. For patients who cannot tolerate statins there are useful combinations of ezetimibe with other drugs affecting lipid metabolism. These combinations improve many metabolic parameters, but more trials should be carried out to reach more robust conclusions about their effects on cardiovascular disease prevention.     

Effects of statins,fibrates, rosuvastatin,and ezetimibe beyond cholesterol: The modulation of LDL size and subclasses in high-risk patients

Increasing evidence suggests that the quality-rather than just the quantity-of low-density lipoproteins (LDLs) exerts a great influence on cardiovascular risk. LDLs comprise multiple subclasses with discrete size and density, and different physicochemical composition, metabolic behaviors, and atherogenicity. Individuals generally cluster into 2 broad subgroups. Most have a predominance of large LDLs, and some have a higher proportion of small particles. Small, dense LDLs are good predictors of cardiovascular events and progression of coronary artery disease. Their predominance has been accepted as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III. Several studies have shown that therapeutic modulation of LDL size and subclass is of great benefit in reducing the risk of cardiovascular events. This seems particularly true for statins and fibrates when they are administered to higher-risk patients, such as those with type 2 diabetes or vascular disease. Data reporting outcomes with the use of rosuvastatin, the latest statin molecule introduced to the market, and ezetimibe, a cholesterol absorption inhibitor, are promising.     

Potential of ezetimibe in memory deficits associated with dementia of Alzheimer's type in mice

Background:

High cholesterol levels have been positively correlated with a higher incidence of memory impairment and dementia.

Aim:

The study was undertaken to investigate the potential of the lipid-lowering drug, ezetimibe, in memory deficits associated with dementia of Alzheimer''s (AD) type in mice.

Methods:

Dementia was induced with chronic administration of a high-fat diet (HFD) or intracebroventricular streptozotocin (ICV STZ, two doses of 3 mg/kg) in separate groups of animals. The memory of the animals was assessed by employing a Morris water maze. Brain thio barbituric acid-reactive species and reduced glutathione levels were measured to assess the total oxidative stress. Brain acetyl cholinesterase (AChE) activity and total serum cholesterol levels were also measured.

Results:

STZ/HFD produced a significant impairment of memory along with an increase in brain AChE activity and oxidative stress. HFD mice also showed an increase in cholesterol levels. Ezetimibe (10 mg/kg, orally for 15 days) significantly attenuated STZ/HFD-induced memory deficits and biochemical changes. It also prevented HFD-induced rise in the cholesterol level.

Conclusions:

The memory-restorative effect of ezetimibe can be attributed to its cholesterol-dependent as well as cholesterol-independent effects. The study highlights the potential of ezetimibe in memory dysfunctions associated with dementia of AD.     

Ezetimibe – new anti-atherogenic properties?

Ezetimibe, a Niemann Pick C1-like1 inhibitor, inhibits cholesterol absorption. The drug has been shown to affect lipid raft function in monocytes and therefore may inhibit lipid accumulation in the atheromatous plaque with a mechanism that is unrelated to its effect in reducing cholesterol absorption. In this issue of the British journal of pharmacology, Gómez-Garre et al. demonstrate that ezetimibe and simvastatin both have a beneficial effect on the atheromatous plaque, which may be due to their effect on both monocyte/macrophage function and reduction in nuclear factor-κB activity. Whether these results in a rabbit model of atherosclerosis can be translated into human atherosclerosis awaits further studies.