Efficacy and safety of ezetimibe added to ongoing statin therapy for treatment of patients with primary hypercholesterolemia

Predictors of uncontrolled hyperlipidaemia in high-risk ambulatory patients in primary care

OBJECTIVE

To determine (a) the proportion of patients at high risk of cardiovascular events who achieve low-density lipoprotein cholesterol (LDL-C) goals as recommended by the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III) guidelines, and (b) the predictors of poor LDL-C control.

METHODS

Two open-label, prospective, non-randomised, observational studies (study 1 with n=19 194 patients, predominantly with coronary artery disease (CHD); study 2 with n=19 484 patients, pre-dominantly with diabetes mellitus (DM)). Patients received, usually after statin pretreatment, ezetimibe 10 mg plus simvastatin as fixed-dose combinations over 3 months. Bivariate and multivariate regression analysis was performed to identify factors associated with poor LDL-C control.

RESULTS

At study end, 38% (up from 4.7% at baseline) of CHD and 35% (up from 3.3% at baseline) of diabetic patients achieved the target LDL value <100 mg/dl (2.6 mmol/l) after treatment with a fixed-dose ezetimibe-simvastatin combination. In both studies, concomitant atherosclerotic disease was associated with good control. Conversely, factors associated with poor control were, among others, high baseline LDL-C values, pretreatment with certain statins, and (in the DM study) high HbA(1c), and high body mass index.

CONCLUSION

Under real world, general practice conditions, a substantial proportion of high-risk patients with CHD and/or DM met LDL-C target levels on dual cholesterol inhibition with ezetimibe/simvastatin. A limited number of easily recognisable factors allow physicians to identify high risk patients whose LDL-C is likely to be difficult to control. Early identification of this patient group may have profound clinical benefits in general practice by enabling specific early interventions such as counselling on physical activity, dietary support and/or follow up visits to the GP.

Ezetimibe: cholesterol lowering and beyond

Ezetimibe is a cholesterol absorption inhibitor that blocks the intestinal absorption of both biliary and dietary cholesterol. It appears to exert its effect by blocking intestinal sterol transporters, specifically Niemann-Pick C1-like 1 proteins, thereby inhibiting the intestinal absorption of cholesterol, phytosterols and certain oxysterols. Ezetimibe monotherapy and in combination with statin therapy is primarily indicated for lowering LDL-cholesterol levels. In addition, it may favorably affect other parameters that could potentially further reduce atherosclerotic coronary heart disease risk, such as raising HDL-cholesterol and lowering levels of triglycerides, non-HDL-cholesterol, apolipoprotein B and remnant-like particle cholesterol. Further effects of ezetimibe include a reduction in circulating phytosterols and oxysterols and, when used in combination with statins, a reduction in high-sensitivity C-reactive protein. The clinical significance of the LDL-cholesterol lowering and other effects of ezetimibe is being evaluated in clinical outcome studies.

Cholesterol lowering is more important than pleiotropic effects of statins for endothelial function in patients with dysglycaemia and coronary artery disease

AIMS

The importance of pleiotropic effects of statins on endothelial function and inflammatory markers was investigated in patients with dysglycaemia and coronary artery disease (CAD).

METHODS AND RESULTS

Thirty-nine patients were randomized to simvastatin 80 mg daily (S80; n = 20) or ezetimibe 10 mg and simvastatin 10 mg daily (E10/S10; n = 19) for 6 weeks, aiming at similar cholesterol reduction. Endothelial function, evaluated by brachial artery flow-mediated vasodilatation (FMD) and the effect of endothelin receptor blockade, serum lipids, and inflammatory markers were evaluated at baseline and follow-up. At follow-up, low-density lipoprotein cholesterol decreased from 3.1 (2.8-3.4) (median and quartiles) to 1.5 mmol/L (1.4-1.7) and from 3.0 (2.5-3.4) to 1.3 mmol/L (1.1-1.8), in the S80 and E10/S10 groups, respectively. In the entire study group, FMD increased from 4.3% (3.4-6.1) at baseline to 5.5% (3.4-6.6) at follow-up, while C-reactive protein decreased from 3.1 (1.7-7.6) to 2.3 mg/L (0.9-6.5). The changes in FMD and C-reactive protein from baseline to follow-up were not significantly different between patients on S80 and E10/S10 groups. Endothelin blockade enhanced endothelium-dependent vasodilatation both at baseline and follow-up.

CONCLUSION

Lipid lowering is more important than pleiotropic effects of statins for improvement in endothelial function and inflammatory markers in patients with dysglycaemia and CAD.

Lipid-altering efficacy of ezetimibe/simvastatin 10/40 mg compared with doubling the statin dose in patients admitted to the hospital for a recent coronary event: the INFORCE study

BACKGROUND

The aim of this study was to investigate the efficacy and safety profile of switching to ezetimibe/simvastatin (Eze/Simva) 10/40 mg compared with doubling the statin dose upon discharge in patients taking a statin and admitted to the hospital for the investigation of a coronary event.

DESIGN

This phase IV, multi-centre, randomised, open-label, active-controlled, parallel group study enrolled 424 patients (aged >/= 18 years) hospitalised for an acute coronary event and taking a stable dose of a statin (>/= 6 weeks) that could be doubled per the product label. Upon discharge from the hospital, patients were stratified by their statin dose/potency (high, medium and low) and randomised 1 : 1 to doubling of the statin dose (n = 211) or Eze/Simva 10/40 mg (n = 213) for 12 weeks. The primary efficacy variable was the absolute low-density lipoprotein cholesterol (LDL-C) value (mmol/l) at study end-point.

RESULTS

Mean baseline LDL-C for the two treatment groups were 2.48 and 2.31 mmol/l for the Eze/Simva and statin groups respectively. At study end-point, least squares mean LDL-C values were 1.74 mmol/l in the Eze/Simva group and 2.22 mmol/l in the statin group resulting in a significant between-group difference of -0.49 mmol/l (p </= 0.001). Eze/Simva 10/40 mg also produced significantly lower total cholesterol (-0.49 mmol/l), non-high-density lipoprotein cholesterol [(non-HDL-C); -0.53 mmol/l] and apolipoprotein B (-0.14 mmol/l) values compared with doubling the statin dose (p </= 0.001 for all). Both treatments produced similar effects on triglycerides, C-reactive protein and HDL-C; the between treatment group differences were not significant (p >/= 0.160). Significantly more patients achieved LDL-C levels < 2.5 (< 100 mg/dl; 86% vs. 72%), < 2.0 (< 77 mg/dl; 70% vs. 42%) and < 1.8 mmol/l (< 70 mg/dl; 60% vs. 31%) with Eze/Simva than statin (all p </= 0.001). Eze/Simva was generally well tolerated, with a safety profile similar to statin. There were no differences in the incidences of liver transaminases >/= 3 x upper limit of normal (ULN) or creatine kinase >/= 10 x ULN between the groups.

CONCLUSIONS

In patients taking a statin and admitted to the hospital for investigation of a coronary event, treatment with Eze/Simva 10/40 mg for 12 weeks produced greater improvements in lipids with a similar safety profile compared with doubling of the statin dose.

Cholesterol goal attainment in patients with coronary heart disease and elevated coronary risk: results of the Hong Kong hospital audit study

OBJECTIVE

We sought to determine 1) long-term lipid-lowering treatment patterns; 2) cholesterol goal attainment rates and possible determinants of goal achievement; and 3) effects of cholesterol goal attainment on coronary events in hospitalized Hong Kong patients.

METHODS

In this retrospective cohort analysis, records of two public Hong Kong hospitals were reviewed for 196 adults (69% with coronary heart disease (CHD) or CHD-risk equivalent) who received at least one lipid-lowering therapy during hospitalization. Low-density lipoprotein cholesterol (LDL-C) targets were <2.6 mmol/l (<100 mg/dL) for patients with CHD or CHD risk equivalents and <3.37 mmol/l (<130 mg/dL) for those without.

RESULTS

Most participants were initiated on regimens of low to midequipotency doses and never had their regimens adjusted to higher potency. Approximately 44% of patients not at LDL-C at baseline failed to achieve goal during a median follow-up of 1.9 years. Patients with higher coronary risk and/or LDL-C levels at baseline were less likely than their lower-risk counterparts to achieve goal; for each 1-mmol/l (38.7-mg/dL) increase in LDL-C at baseline, the likelihood of attaining goal declined by 64%. Patients achieving cholesterol goal had significantly longer cardiovascular event-free times.

CONCLUSIONS

A total of 44% of Hong Kong patients not at LDL-C goals at baseline did not achieve them over 1.9 years. More effective and well-tolerated therapies, including adjunctive regimens (e.g., ezetimibe-statin, niacin-statin), may be necessary to enhance LDL-C goal achievement and increase event-free time.

Madin-Darby canine kidney II cells: a pharmacologically validated system for NPC1L1-mediated cholesterol uptake

Absorption of dietary cholesterol in the proximal region of the intestine is mediated by Niemann-Pick C1-like protein (NPC1L1) and is sensitive to the cholesterol absorption inhibitor ezetimibe (EZE). Although a correlation exists between EZE binding to NPC1L1 in vitro and efficacy in vivo, the precise nature of interaction(s) between NPC1L1, EZE, and cholesterol remain unclear. Here, we analyze the direct relationship between EZE analog binding to NPC1L1 and its influence on cholesterol influx in a novel in vitro system. Using the EZE analog [(3)H]AS, an assay that quantitatively measures the expression of NPC1L1 on the cell surface has been developed. It is noteworthy that whereas two cell lines (CaCo-2 and HepG2) commonly used for studying NPC1L1-dependent processes express almost undetectable levels of NPC1L1 at the cell surface, polarized Madin-Darby canine kidney (MDCKII) cells endogenously express 4 x 10(5) [(3)H]AS sites/cell under basal conditions. Depleting endogenous cholesterol with the HMG CoA reductase inhibitor lovastatin leads to a 2-fold increase in the surface expression of NPC1L1, supporting the contention that MDCKII cells respond to changes in cholesterol homeostasis by up-regulating a pathway for cholesterol influx. However, a significant increase in surface expression levels of NPC1L1 is necessary to characterize a pharmacologically sensitive, EZE-dependent pathway of cholesterol uptake in these cells. Remarkably, the affinity of EZE analogs for binding to NPC1L1 is almost identical to the IC(50) blocking cholesterol flux through NPC1L1 in MDCKII cells. From a mechanistic standpoint, these observations support the contention that EZE analogs and cholesterol share the same/overlapping binding site(s) or are tightly coupled through allosteric interactions.

Combination therapy in cholesterol reduction: focus on ezetimibe and statins

Although widely used in lipid lowering therapy, HMG CoA reductase inhibitors (even when administered at high doses) are frequently insufficient to achieve guideline-recommended LDL-C goals for many patients with hypercholesterolemia in everyday clinical practice. Many patients do not achieve LDL-C goal on the initial dose of statin and the majority of these patients does not reach their goal after 6 months. As a consequence, a wide therapeutic gap exists between target LDL-C levels and those typically achieved in clinical practice. A recent and more effective therapeutic hypocholesterolemic strategy is to treat the two main sources of cholesterol simultaneously (production of cholesterol, mainly in the liver, and absorption of cholesterol in the intestine) with a complementary mechanism of action, by co-administering ezetimibe, a novel agent inhibiting cholesterol absorption, with a statin, which inhibits cholesterol production in the liver. Ezetimibe can be effectively and safely co-administered with any dose of any statin and, compared with the single inhibition of cholesterol production, afforded by statins alone, provides consistently greater reductions in LDL-C through dual inhibition of both cholesterol production and absorption. We summarize the pivotal role of both the liver and intestine in the overall balance of cholesterol in the body and describe the clinical impact and relevance of using ezetimibe either alone or co-administered with statins in controlling elevated levels of plasma LDL cholesterol.

Ezetimibe-associated adverse effects: what the clinician needs to know

OBJECTIVE

Ezetimibe is a relatively new lipid lowering agent, which is indicated for the treatment of primary hypercholesterolaemia, either as monotherapy or in combination with other hypolipidaemic drugs. The objective of the present article was to review the side effects attributed to ezetimibe administration and discuss their possible underlying mechanisms. Moreover, we aimed to comment on the possible drug interactions of ezetimibe and present current guidelines regarding its safe use.

METHODS

Relevant articles were identified through a PubMed search (up to June 2007).

RESULTS

Compelling evidence from the majority of the data reviewed here showed that adverse effects associated with ezetimibe use are few and mild without having been associated with serious clinical outcomes. In most studies ezetimibe has not been associated with increased rates of myopathy or rhabdomyolysis, whether used alone or in combination with statins, although there have been some case reports of myopathy attributed to this agent. Moreover, ezetimibe has been associated with mild elevations of liver transaminases, mainly in combination with a statin. Other side effects are extremely rare. It should be noted, however, there are no long-term safety data or outcome studies for ezetimibe yet.

CONCLUSIONS

Ezetimibe is a safe alternative option for hyperlipidaemic patients intolerant to other lipid lowering drugs as well as a beneficial supplementary agent for patients who do not reach the recommended serum cholesterol level with their current hypolipidaemic treatment. However, as is the case with all new medications, physicians should be alert to recognise adverse effects associated with ezetimibe and report them to regulatory authorities.

Ezetimibe, a selective inhibitor of the transport of cholesterol

Niemann-Pick C1-like 1 (NPC1L1) has recently been identified and has been shown to have features of a plasma membrane transporter, including a secretion signal, 13 predicted transmembrane domains, extensive N-linked glycosylation sites and a sterol-sensing domain. It is highly expressed on the surface of absorptive jejunal enterocytes. NPC1L1 has been shown to be a direct target of ezetimibe, and an ezetimibe-sensitive pathway plays a role in intestinal cholesterol absorption. Ezetimibe-based therapy represents an exciting new area in the treatment of dyslipidemia.

Efficacy and safety of ezetimibe and ezetimibe plus statin therapy in patients aged under 65, 65–74 and 75 years and older

Although the greatest burden of cardiovascular disease occurs after age 65 years, limited efficacy and safety data are available for cholesterol-lowering drugs in elderly patients. We undertook a pooled analysis of individual data from 13,282 patients aged 18–93 years in 16 published trials of ezetimibe and ezetimibe added on to or coadministered with a statin (ezetimibe/statin). Overall, ezetimibe reduced low-density lipoprotein cholesterol by 20% compared with placebo and ezetimibe/statin reduced low-density lipoprotein cholesterol by 17% compared with a statin alone, with consistent treatment effects across age groups (<65, 65–74 and ≥75 years). Rates of any adverse or drug-related adverse events were also similar across age groups. We conclude that the lipid efficacy and safety of ezetimibe and ezetimibe/statin in those aged 65–74 and 75 years and older are similar to those observed in patients aged under 65 years.

A retrospective study of the lipid-lowering efficacy and safety of ezetimibe added to hydroxy methylglutaryl coenzyme A reductase therapy in HIV-infected patients with hyperlipidemia

BACKGROUND

Abnormalities in lipid metabolism are a well-described consequence of human immunodeficiency virus (HIV) infection being treated with highly active antiretroviral therapies (HAART).

OBJECTIVE

The purpose of this study is to evaluate the lipid-lowering efficacy and safety of ezetimibe added to existing hydroxy methylglutaryl coenzyme A reductase (statin) therapy in HIV-infected patients with hyperlipidemia.

METHODS

This is a retrospective study utilizing a comprehensive electronic patient registry to identify all adult HIV-infected patients seen at the Dallas Veterans Affairs (VA) Medical Center during a 4-year period from October 1, 2002 through October 1, 2006.

RESULTS

A total of 26 HIV-infected patients initiated on ezetimibe 10 mg were identified, with 14 adult males meeting strict criteria for inclusion. Median age was 54 years (interquartile range [IQR], 45-59) with a median duration of HIV of 13 years, CD4 count of 513 cells/mm(3) (IQR, 289-736), and 9 of 14 patients had undetectable viral loads at baseline. Initiation of ezetimibe 10 mg resulted in a significant decrease in total cholesterol (TC) from baseline (-12.9%, P = 0.001); low-density lipoprotein cholesterol (LDL-C; -25.7%, P = 0.001); and non-high-density lipoprotein cholesterol (non-HDL-C; -23.9%, P = 0.001). There was also a nonsignificant decrease in triglycerides (15.8%, P = 0.43), and an increase in number of patients achieving National Cholesterol Education Program/Adult Treatment Panel III goal for LDL-C after initiation of ezetimibe (+20.9%, P = 0.125). These improvements occurred without adverse effects or changes in virologic and immunologic control.

CONCLUSION

Addition of ezetimibe to existing statin therapy in HIV-infected VA patients treated with HAART significantly reduces TC, LDL-C, and non-HDL-C concentrations without apparent side effects or compromising of virologic control.

Lipid-modifying therapy and attainment of cholesterol goals in Hungary: the return on expenditure achieved for lipid therapy (REALITY) study

BACKGROUND AND OBJECTIVE

Cardiovascular disease is a leading cause of death in Eastern Europe. Few studies on cholesterol goal achievement have been conducted in Hungarian clinical settings. This study set out to evaluate lipid-modifying therapy practices and their effects on total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) goal attainment in Hungarian patients with coronary heart disease (CHD), CHD risk equivalents, or >or=2 coronary risk factors.

METHODS

This multicentre observational study involved patients receiving lipid-modifying therapy who were under the care of general practitioners (n = 300) or specialists (n = 140). Physician questionnaires were used to collect data on baseline patient characteristics, including laboratory parameters. Using validated cardiovascular risk assessment measures, patients were stratified into high-risk (10-year absolute coronary risk >20%; n = 367) and lower risk groups (n = 73). Cholesterol goals were TC <4.5 mmol/L (<175 mg/dL) and LDL-C <2.5 mmol/L (<100 mg/dL) for the high-risk group and TC <5.0 mmol/L (<193 mg/dL) and LDL-C <3.0 mmol/L (<117 mg/dL) for those at lower risk.

RESULTS

Among 440 patients (n = 312 with CHD or CHD risk equivalents), 374 (85%) were initiated on HMG-CoA reductase inhibitors (statin monotherapy), 44 (10%) received fibric acid derivatives and 22 (5%) received combination regimens. Although >50% of patients needed >35% TC lowering to reach goal, <10% of patients received high or very high potency lipid-modifying regimens or combination regimens initially. A total of 116 (26.4%) patients achieved their TC goals after >/=1 year of treatment, including 27.9% of patients with CHD/risk equivalents and 22.7% of those with risk factors only. Sixty-six (15%) patients achieved goal on initial lipid-modifying regimens, while a further 50 (11.4%) achieved goal following treatment changes, including upward dosage adjustments.

CONCLUSION

Approximately 74% of Hungarian patients receiving lipid-modifying therapy in our study did not achieve cholesterol goals. The proportion of patients realising their TC goals was higher in those treated by specialists but still did not exceed one-third.

EP2306 [2-(4-Biphenyl)-4-methyl-octahydro-1,4-benzoxazin-2-ol, hydrobromide], A Novel Squalene Synthase Inhibitor, Reduces Atherosclerosis in the Cholesterol-Fed Rabbit

EP2306 [2-(4-biphenyl)-4-methyl-octahydro-1,4-benzoxazin-2-ol, hydrobromide] inhibits squalene synthase and lipid biosynthesis and possesses antioxidant properties. We hypothesized that EP2306 can effectively modify circulating lipids and reduce atherosclerosis in the cholesterol-fed rabbit. Animals were fed a high-cholesterol diet for 4 weeks followed by 4 (phase 1 and 2) or 12 weeks (phase 3) of drug treatment while on high-cholesterol diet. In phase 1, the dose-effect relationship of EP2306 on lipids and atherosclerosis was established, and its most effective dose was determined (2 mg/kg). This dose reduced significantly total cholesterol (512 +/- 96 mg/dl before versus 320 +/- 124 mg/dl after treatment, p < 0.05) and atherosclerotic lesions compared with control animals. In phase 2, the effects of 2 mg/kg EP2306, 2.5 mg/kg simvastatin, and their combination were assessed. Although no significant effect on lipid parameters was observed, there was a significant reduction (35 +/- 5%, p < 0.05) of atherosclerotic lesions in animals treated with EP2306, a similar reduction with simvastatin, and a further reduction (48 +/- 7%, p < 0.05) when the two agents were combined. In animals treated for 12 weeks with the drugs (phase 3), only EP2306 significantly reduced atherosclerotic lesions by more than 50%, whereas simvastatin alone or in combination with EP2306 had no effect. Treatment with EP2306 did not adversely affect liver transaminases or cause any histopathological changes on various organs of the animals. In conclusion, we have shown that EP2306 inhibits atherosclerosis in vivo, indicating potential as a novel therapeutic agent for coronary artery disease and other atherosclerosis-related disorders.

Ezetimibe: an update on the mechanism of action, pharmacokinetics and recent clinical trials

Elevated serum cholesterol is a known risk factor for the development of coronary artery disease. Circulating cholesterol is a product of both cholesterol absorption from the gut and cellular cholesterol production. Ezetimibe is a novel cholesterol-lowering drug that acts at the brush border of the small intestine. Recent studies have further identified the molecular target as the Niemann-Pick C1-like transporter. Ezetimibe blocks the absorption of dietary and biliary cholesterol and plant sterols resulting in intracellular cholesterol depletion. Clinical studies have demonstrated beneficial improvements in the lipid profile with ezetimibe as monotherapy, but dramatic effects are seen when ezetimibe is combined with other lipid-lowering drugs, particularly 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). Combination studies of ezetimibe with statins, bile acid sequestrants, fenofibrate and niacin all demonstrate significant total and low density lipoprotein cholesterol lowering. An excellent safety and tolerability profile combined with once-daily dosing make this attractive adjunct therapy for the treatment of hypercholesterolemia.

Effect of ezetimibe in patients who cannot tolerate statins or cannot get to the low density lipoprotein cholesterol target despite taking a statin

BACKGROUND

Recent guidelines underline the need for high-risk patients to reach strict low density lipoprotein cholesterol (LDL-C) targets (1.8-2.6 mmol/L; 70-100 mg/dL), and specifically mention the possible use of combination therapy (e.g.statin + ezetimibe) to achieve these goals.

METHODS

A retrospective case-note audit was carried out to assess the response to administering ezetimibe in patients unable to tolerate statins (Group 1), or high dose of statins (Group 2) and patients who cannot achieve the LDL-C target (2.6 mmol/L; 100 mg/dL) despite taking a statin (Group 3).

RESULTS

Ezetimibe lowered LDL-C levels by 20-29% across the 3 patient groups after 2-3 months of treatment. High density lipoprotein cholesterol (HDL-C) levels tended to remain unchanged, although there was a consistent trend for a fall if baseline values were 'high'. However, the LDL-C/HDL-C ratio changed significantly and favourably in all groups. The fall in fasting triglyceride levels in all groups was greater (reaching 19-25%) when baseline levels were > or = 1.5 or 1.7 mmol/L (136-150 mg/dL). There were no marked abnormalities in liver function tests or creatine kinase activity. In Group 3 there was a significant trend for a fall in serum creatinine levels across the tertiles of baseline creatinine values. Limitations of the present study include the small sample size (especially in Groups 1 and 2), its short-term duration and the absence of event-based end-points. Therefore, the results are hypothesis-generating rather than conclusive.

CONCLUSIONS

When used alone or added to a statin, ezetimibe favourably altered the LDL-C/HDL-C ratio and lowered triglyceride levels. Ezetimibe was well tolerated in patients with statin intolerance and was associated with a 26% fall in LDL-C. An additional action may be some degree of improved renal function. Further studies are needed to confirm these findings.

A multi-centre, randomised, double-blind 14-week extension study examining the long-term safety and efficacy profile of the ezetimibe/simvastatin combination tablet

The objective of this study was to compare the efficacy and safety profile of ezetimibe/simvastatin (EZE/SIMVA) tablet and SIMVA monotherapy. This was an extension study of a randomised, double-blind, placebo-controlled study in patients with primary hypercholesterolaemia. Protocol-compliant patients who completed the 12-week base study were eligible to enter a randomised, double-blind, 14-week extension study and were administered 1 of 8 daily treatments: EZE/SIMVA 10/10-, 10/20-, 10/40- or 10/80-mg, or SIMVA 10-, 20-, 40- or 80-mg. Patients receiving these treatments during the base study remained on the same treatment in the extension. Patients administered placebo or EZE 10-mg monotherapy during the base study were re-randomised to EZE/SIMVA 10/10 mg or SIMVA 80 mg. The primary analysis was mean per cent change in low-density lipoprotein cholesterol (LDL-C) from baseline to extension study end-point. Mean changes from baseline in LDL-C of -38.8% and -53.7% were observed for pooled SIMVA and pooled EZE/SIMVA respectively. The between treatment difference of -14.9% (95% confidence interval: -16.4, -13.3) was statistically significant (p < 0.001). The incremental LDL-C lowering effect of EZE/SIMVA compared with the corresponding dose of SIMVA alone was consistent across the dose range (p < 0.001 for each between-group comparison). More patients receiving EZE/SIMVA than SIMVA achieved LDL-C concentrations < 100 mg/dl and < 70 mg/dl (p < 0.001 for both goals). EZE/SIMVA was generally well tolerated with a safety profile similar to SIMVA monotherapy. There were no significant between-group differences in the incidences of clinically significant elevations in liver transaminase or creatine kinase levels. In conclusion, EZE/SIMVA had a comparable safety and tolerability profile and was more efficacious than SIMVA monotherapy for up to 6 months.

Postprandial lipemia: an under-recognized atherogenic factor in patients with diabetes mellitus

Atherosclerotic disease is the leading cause of both morbidity and mortality in patients with type 2 diabetes. In these patients, postprandial dyslipidemia include not only quantitative but also qualitative abnormalities of lipoproteins which are potentially atherogenic and seems to be a significant risk factor for cardiovascular disease since there is evidence that it results in endothelial dysfunction and enhanced oxidative stress. The most common pattern of postprandial dyslipidemia in diabetes consists of high concentrations of triglycerides, higher VLDLs production by the liver and a decrease in their clearance, a predominance of small dense LDL particles, and reduced levels of HDL. The cause of this postprandial dyslipidemia in diabetes is complex and involves a variety of factors including hyperinsulinemia, insulin resistance, hyperglycemia and disturbed fatty acid metabolism. Numerous clinical studies have shown that postprandial dyslipidemia is associated with endothelial dysfunction in type 2 diabetes and with alterations in other surrogate markers in the cascade of atherosclerosis. Current published guidelines indicate that in diabetics the primary lipid target is LDL<100 mg/dL (70 mg/dL in very high-risk patients) and the most appropriate class of drugs are statins although the issue of postprandial dyslipidemia has not been specifically addressed so far. Moreover, several other classes of medications (fibrates, niacin and antidiabetic drugs) as well as non-pharmacological interventions (i.e. diet, smoking cessation and exercise) can be used to treat lipid and lipoprotein abnormalities associated with insulin resistance and type 2 diabetes. These type of interventions may be more appropriate to ameliorate postprandial dyslipidemia. However, this remains to be confirmed on clinical grounds.

Ezetimibe: rationale and role in the management of hypercholesterolemia

Elevated low-density lipoprotein (LDL) cholesterol plays an important role in the development of atherosclerosis. In part, plasma LDL levels are dependent on cholesterol absorption in the intestine and the rate of intrinsic cholesterol synthesis. Therapy with 3-hydroxy-3-methylglutaryl coenzyme A-reductase inhibitors has often proven to be successful in reducing plasma LDL levels. However, a significant number of patients do not reach their target LDL levels despite statin therapy. As is reviewed, drugs that inhibit cholesterol absorption are a useful adjunct to lipid-lowering therapy by statins. This review discusses the mechanisms involved in intestinal absorption of cholesterol and its transport as potential targets of newer agents that affect cholesterol absorption. The use of bile acid sequestrants and esters of plant stanols, as well as other intestinally active agents for reducing plasma LDL levels, has been limited by side effects and difficulties in patient compliance. In contrast, the new selective cholesterol transporter inhibitor ezetimibe has been demonstrated to reduce plasma LDL alone or in combination with statins without significant adverse effects. In spite of the robust lipid-lowering data with ezetimibe, questions about clinical outcomes, safety, and efficacy in various combinations remain.

Efficacy of ezetimibe/simvastatin 10/20 and 10/40 mg compared with atorvastatin 20 mg in patients with type 2 diabetes mellitus

AIM

This randomized, double-blind study evaluated the efficacy of switching from atorvastatin (ATV) 10 mg to ezetimibe/simvastatin (EZE/SIMVA) 10/20 mg, EZE/SIMVA 10/40 mg or doubling the dose of ATV from 10 to 20 mg in patients with type 2 diabetes (T2D).

METHODS

Eligible patients had haemoglobin A(1C)< or =10%, were aged > or =18 years and were on ATV 10 mg for > or =6 weeks before study entry. After a 4-week open-label ATV 10 mg run-in, patients were randomized to EZE/SIMVA 10/20 mg (n = 220), EZE/SIMVA 10/40 mg (n = 222) or ATV 20 g (n = 219) daily for 6 weeks.

RESULTS

Greater (p < or = 0.001) reductions in low-density lipoprotein cholesterol (LDL-C) (the primary end-point) were achieved by switching to EZE/SIMVA 10/20 mg (26.2%) or 10/40 mg (30.1%) than by doubling the dose of ATV to 20 mg (8.5%). EZE/SIMVA 10/20 mg and 10/40 mg produced greater (p < or = 0.001) reductions in total cholesterol, non-high-density lipoprotein cholesterol (HDL-C) and apolipoprotein B relative to ATV 20 mg. A reduction (p < or = 0.050) in C-reactive protein was observed with EZE/SIMVA 10/40 mg vs. ATV 20 mg. Similar reductions in triglycerides were observed across the three groups, and none of the treatments produced a significant change in HDL-C. A greater (p < or = 0.001) proportion of patients achieved LDL-C <2.5 mmol/l with EZE/SIMVA 10/20 mg (90.5%) and 10/40 mg (87.0%) than with ATV 20 mg (70.4%). Both EZE/SIMVA doses were generally well tolerated, with an overall safety profile similar to ATV 20 mg.

CONCLUSIONS

EZE/SIMVA 10/20 and 10/40 mg provided greater lipid-altering efficacy than doubling the dose of ATV from 10 to 20 mg and were well tolerated in patients with T2D.

Dyslipidemia in type 2 diabetes mellitus

Cardiovascular disease is a significant cause of morbidity and mortality in patients with diabetes mellitus (DM). DM is now recognized as a risk equivalent for coronary heart disease. The lipid profile in patients with type 2 DM is characterized by elevated triglycerides, low levels of high-density lipoprotein cholesterol, and small dense low-density lipoprotein cholesterol (LDLC) particles and is believed to be a key factor promoting atherosclerosis in these patients. Both primary and secondary prevention studies have provided ample evidence that aggressive statin therapy reduces cardiovascular end points in patients with DM. In all persons with DM, current treatment guidelines recommend reduction of LDLC to less than 100 mg/dL, regardless of baseline lipid levels. Lowering LDLC to less than 70 mg/dL may provide even greater benefits, particularly in very high risk patients with DM and coronary heart disease.

Cholesterol reduction yields clinical benefits: meta-analysis including recent trials

BACKGROUND

Previous meta-analyses reported by Gould et al found significant decreases of 15% in the risk for coronary heart disease (CHD)-related mortality and 11 % in risk for all-cause mortality per decrease of 10% in total cholesterol (TC) level.

OBJECTIVE

To evaluate the effects of reducing cholesterol on clinical events after including data from recent clinical trials.

METHODS

Using a literature search (MeSH key terms, including: bezafibrate, coronary disease, efficacy, gemfibrozil, hydroxymethylglutaryl-CoA reductase inhibitors, hypercholesterolemia, niacin [nicotinic acids], randomized controlled trials, and treatment outcome; years: 1999-2005), we identified trials published in English that assessed the effects of lipid-modifying therapies on CHD end points, including CHD-related death, myocardial infarction, and angina pectoris. We also included all studies from the previously published meta-analysis. Using the same analytic approach as previously, we determined the effects of net absolute reductions (1 mmol/L [38.7 mg/dL]) in TC and low-density lipoprotein cholesterol (LDL-C) on the relative risks (RRs) for all-cause mortality, CHD-related mortality, any CHD event (mortality or nonfatal myocardial infarction), and non-CHD-related mortality.

RESULTS

We included 62 studies involving 216,616 patients, including 126,474 from 24 randomized controlled trials the findings of which were published since the previous meta-analysis (1998). Among all patients, for every 1-mmol/L decrease in TC, there was a 17.5 reduction in RR for all-cause mortality; 24.5 %, for CHD-related mortality; and 29.5% for any CHD event. Corresponding reductions for every 1-mmol/L decrease in LDL-C were 15.6%, 28.0%, and 26.6%, respectively. Similar relationships were observed in patients without CHD. No significant relationship was found between lipid reduction and non-CHD-related mortality risk.

CONCLUSIONS

The results from the present analysis support conclusions from previous meta-analyses that cholesterol lowering is clinically beneficial in patients with CHD or at elevated CHD risk. These results also support the previous finding that non-CHD-related mortality is unrelated to lipid reductions.

Dual cholesterol inhibition with ezetimibe/simvastatin in pre-treated hypercholesterolaemic patients with coronary heart disease or diabetes mellitus: prospective observational cohort studies in clinical practice

OBJECTIVE

Patients with primary hypercholesterolaemia and concomitant coronary heart disease (CHD) and/or diabetes mellitus (DM), who are at particularly high risk of cardiovascular events such as stroke or myocardial infarction, benefit from aggressive lipid lowering strategies. The present studies investigated the incremental efficacy and safety of dual cholesterol inhibition with ezetimibe/simvastatin in such high-risk patients pre-treated with statins but not reaching the 100 mg/dL (2.6 mmol/L) low density cholesterol (LDL-C) cholesterol threshold in the primary care setting.

METHODS

Two open-label, prospective, non-randomised, observational studies (study 1 with n = 19 194 patients, predominantly with CHD; study 2 with n = 19 484 patients, predominantly with DM). Patients received--almost all after statin pre-treatment--ezetimibe 10 mg plus simvastatin 10 mg (study 1: 15%, study 2: 16%), 20 mg (in 68% each), 40 mg (12%/10%) or 80 mg (1%/1%) as fixed dose combinations over 3 months (dosage at investigator's discretion).

RESULTS

Mean LDL-C was reduced by 28%/27% (study 1/ study 2) compared with baseline values (on statin monotherapy). Mean total cholesterol was decreased by 22% in each study, mean triglycerides by 16/17%, and mean high density cholesterol (HDL-C) was increased by 9/10%. Adverse events were reported in 0.3% and 0.2% of patients, respectively.

CONCLUSION

Dual cholesterol inhibition with ezetimibe/simvastatin was effective and well tolerated under real practice conditions in high-risk patients with CHD and/or DM.

Safety considerations with gastrointestinally active lipid-lowering drugs

Gastrointestinally active agents such as cholesterol absorption inhibitors (CAIs) (eg, ezetimibe) and bile acid sequestrants (BAS) (the resins cholestyramine and colestipol, or colesevelam, a nonabsorbable polymer) offer important options for lipid-lowering therapy. Ezetimibe is a novel CAI that inhibits the absorption of dietary and biliary cholesterol without affecting the absorption of triglycerides or fat-soluble vitamins. In clinical trials, there has been no evidence of increased rates of myopathy or rhabdomyolysis associated with ezetimibe, whether in use as monotherapy or in a combination with statin therapy, although there exist case reports of possible ezetimibe-associated myopathy. Ezetimibe alone does not appear to increase liver transaminase levels significantly, but the coadministration of a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) with ezetimibe marginally increases this risk. However, reported increases in liver enzymes have not been associated with clinically meaningful symptoms and often return to baseline levels after the discontinuation of therapy or with continued treatment. To date, no cases of liver failure, liver transplantation, or death have been reported. BAS have been used clinically since the 1960s for lowering low-density lipoprotein cholesterol. Because they are not absorbed from the gastrointestinal tract into the blood, these agents do not contact most body organs and are therefore systemically safe. However, case reports and pharmacokinetic data disclose 3 kinds of adverse effects: (1) the decreased absorption of concomitant medications and sometimes of certain vitamins; (2) the physicochemical alteration of intestinal contents leading to constipation and, very rarely, intestinal obstruction; and (3) modest increases in plasma triglyceride levels due to the alteration of hepatic lipid metabolism. The newest BAS, colesevelam, has greater specificity for bile acids compared with the older agents cholestyramine and colestipol, eliminating most drug interactions and reducing the tendency for constipation. Overall, CAIs and BAS have excellent systemic safety profiles when used alone or in combination with other lipid-lowering drugs.

[New insights and perspectives in the management of dyslipidemia]

PURPOSE

Recent end point trials of lipid-lowering drugs have shown that patients at very high-risk for coronary disease benefit from treatments that lowers low density lipoprotein cholesterol (LDL cholesterol) plasma levels< or =70 mg/dl and that patients with at least 2 risk factors benefit from LDL cholesterol levels< or =100 mg/dl. Epidemiologic studies have shown that the concentration of high density lipoprotein cholesterol (HDL cholesterol) is a strong, independent, inverse predictor of coronary disease risk. Innovative pharmacological approaches to raise low HDL cholesterol levels are currently of considerable interest, especially for patients with type 2 diabetes or metabolic syndrome.

RESULTS

Rosuvastatin has shown superior efficacy in lowering LDL cholesterol, although evidence of clinical benefit is actually lacking. Ezetimibe is a lipid-lowering drug that inhibits absorption of dietary and biliary cholesterol. Its co-administration with statin has given very interesting results. Niacin is the most effective of currently available options for raising HDL cholesterol, although tolerability can be an issue, with serious side effects such as loss of glucose control and liver toxicity. Flushing may occur in 80% of treated patients. Two CETP inhibitors have shown therapeutical efficacy to raise HDL cholesterol, but clinical benefit remains uncertain.

The effect of simvastatin, ezetimibe and their combination on the lipid profile, arterial stiffness and inflammatory markers

OBJECTIVE

Arterial stiffness and highly sensitive C-reactive protein (hsCRP) serum level predict the risk for cardiovascular events. The most commonly used drugs for lowering cholesterol levels, the statins, also have anti-inflammatory effects and can decrease arterial stiffness. Ezetimibe is the first drug of a new class of cholesterol absorption inhibitors in common use and, to date, its effect on arterial stiffness has not yet been studied. The aim of this study was to compare the effect of simvastatin and ezetimibe, both singly and in combination, on arterial stiffness and hsCRP serum concentration in hypercholesterolemic patients.

METHODS

Forty hypercholesterolemic patients were studied. Group1 comprised previously untreated patients, who received simvastatin at doses of 40 mg/day during the study; group 2 comprised patients previously treated with simvastatin at 40 mg/day, who received simvastatin at 80 mg/day during the study; group 3 consisted of patients previously untreated, who received ezetimibe at doses of 10 mg/day during the study; group 4 comprised patients previously treated with simvastatin at 40 mg/day, who received simvastatin at 40 mg/day and ezetimibe at 10 mg/day during the study. Arterial stiffness expressed as the Augmentation Index (AIx) (assessed by pulse wave analysis), the lipid profile and the hsCRP level were measured at baseline and after 3 months of treatment.

RESULTS

The reduction in low-density lipoprotein (LDL) after treatment was significantly greater in groups 1 and 4 (39.9 and 35.7%) than in groups 2 and 3 (17.7 and 16.9%; p = 0.005). The AIx decreased significantly only in group 1 patients, from 30.2 +/- 8.3% before treatment to 21.6 +/- 6.5% after treatment (p < 0.001). Changes in hsCRP paralleled the changes in AIx, with a significant decrease in patients in group 1 only, from 2.8 +/- 2.5 mg/L before treatment to 1.6 +/- 1.5 mg/L after treatment (p = 0.016).

CONCLUSION

Ezetimibe as a monotherapy had no effect on arterial stiffness or hsCRP, while the administration of simvastatin at 40 mg per day improved arterial stiffness and CRP. However, increasing the dose of simvastatin or administering ezetimibe in combination with simvastatin had no beneficial effects on arterial stiffness.

Cytochrome P450s and cholesterol homeostasis

By participating in pathways of cholesterol biosynthesis and elimination, different cytochrome P450 (P450 or CYP) enzymes play an important role in maintenance of cholesterol homeostasis. CYP51 is involved in cholesterol biosynthesis, whereas CYP 7A1, 27A1, 46A1, 7B1, 39A1, and 8B1 are the key enzymes in cholesterol catabolism to bile acids, the major route of cholesterol elimination in mammals. Cholesterol transformations to steroid hormones are also initiated by the P450 enzyme CYP11A1. Finally, one of the major drug-metabolizing P450s CYP3A4 seems to contribute to bile acid biosynthesis as well. The 9 P450s will be the focus of this review and assessed as drug targets for cholesterol lowering.

Lipoprotein effects of combined ezetimibe and colesevelam hydrochloride versus ezetimibe alone in hypercholesterolemic subjects: a pilot study

Two drug classes act in the intestine to lower cholesterol. Ezetimibe inhibits cholesterol absorption, whereas bile acid-binding resins enhance cholesterol excretion via enhanced conversion to bile acids. Combining these 2 classes may be beneficial, but cholestyramine binds ezetimibe, and the combined effect of colesevelam hydrochloride and ezetimibe was little studied. The aim of the study was to determine if adding colesevelam HCl to ezetimibe provides additional lowering of low-density lipoprotein- and apolipoprotein B-containing lipoproteins or alters ezetimibe levels. Twenty subjects with low-density lipoprotein cholesterol (LDL-C) levels of 130 mg/dL or higher were enrolled and taught a National Cholesterol Education Program Step I diet. At a second baseline visit, lipoproteins were measured and subjects were randomly allocated to (1) ezetimibe 10 mg daily with placebo colesevelam HCl twice daily (E) or (2) ezetimibe 10 mg daily with 1.875 g colesevelam HCl twice daily (E + C). Lipoproteins were measured 6 and 12 weeks after initiating treatment. Baseline characteristics (mean +/- SD) were statistically indistinguishable in E vs E + C: LDL-C (mg/dL), 167 +/- 26 and 158 +/- 27; triglyceride, 134 +/- 75 and 140 +/- 67; and BMI, 29.4 +/- 4.9 and 27.8 +/- 6.6 kg/m(2), respectively. Percent changes after 12 weeks in E vs E + C were as follows: LDL-C, -24 +/- 12 vs -30 +/- 11 (P = .102); triglyceride, -19 +/- 34 vs 36 +/- 85 (P = .054; at 6 weeks, P = .009); total cholesterol, -19 +/- 9 vs -15 +/- 8 (P = .50); non-high-density lipoprotein cholesterol, -25 +/- 10 vs -21 +/- 11 (P = .70); apolipoprotein B, -31 +/- 14 vs -22 +/- 14 (P = .41). Plasma ezetimibe levels at 12 weeks were 21% lower in E + C vs E, a nonsignificant difference (P = .54). In conclusion, in the short term, colesevelam HCl may not consistently add cholesterol-lowering benefit to ezetimibe. This observation requires confirmation.

Efficacy and tolerability of ezetimibe 10 mg/day coadministered with statins in patients with primary hypercholesterolemia who do not achieve target LDL-C while on statin monotherapy: A Canadian, multicentre, prospective study--the Ezetrol Add-On Study

BACKGROUND

For patients who have above-target low-density lipoprotein cholesterol (LDL-C) levels while on statin monotherapy, coadministration of a cholesterol absorption inhibitor with the statin may decrease serum LDL-C levels and improve overall lipid profiles.

OBJECTIVES

To assess the effectiveness and safety of ezetimibe 10 mg/day coadministered with a statin in patients with primary hypercholesterolemia who have higher than recommended LDL-C levels while on statin monotherapy.

METHODS

A six-week, prospective, multicentre study of eligible patients who had above-target LDL-C levels while on monotherapy with any statin, regardless of dose, for a minimum of four weeks. All patients were treated for six weeks with 10 mg ezetimibe daily coadministered with their current statins.

RESULTS

A total of 1141 patients were screened, 953 (83.5%) fulfilled the study inclusion criteria and 837 (87.8%) completed the study. Reasons for withdrawal included: lost to follow-up (50 patients [5.2%]); protocol violations (45 patients [4.7%]); adverse events (19 patients [2.0%]); and withdrawal of consent (two patients [0.2%]). After six weeks of treatment, statistically significant (P = 0.001) mean reductions were observed in LDL-C (30.05%), total cholesterol (20.84%), triglycerides (10.16%), apolipoprotein B (19.84%) and the total cholesterol to high-density lipoprotein cholesterol ratio (19.88%). At six weeks, 674 patients (80.5%) achieved target LDL-C levels. Fifty predominantly mild, nonserious adverse events related to ezetimibe were reported by 32 patients (3.4%). Frequently reported adverse events included constipation (n = 7 [0.7% of patients]), diarrhea (n = 4 [0.4%]) and dizziness (n = 4 [0.4%]).

CONCLUSION

Ezetimibe coadministered with statins is effective in reducing LDL-C in patients who do not attain target LDL-C levels while on statin monotherapy.

C-reactive protein (CRP)-lowering agents

C-reactive protein (CRP) plays a role in the pathogenesis of cardiovascular disease. It is a marker and predictor of cardiovascular disease. CRP possesses numerous cardiovascular effects (clotting, generation of oxygen radicals, increase in the expression of adhesion molecules and plasminogen activator inhibitor-1, plaque destabilization) that could result in cardiovascular disease. This review describes the effects of various cardiovascular drugs on the levels of CRP in health and disease. Cyclooxygenase inhibitors (aspirin, rofecoxib, celecoxib), platelet aggregation inhibitors (clopidogrel, abciximab), lipid lowering agents (statins, ezetimibe, fenofibrate, niacin, diets), beta-adrenoreceptor antagonists and antioxidants (vitamin E), as well as angiotensin converting enzyme (ACE) inhibitors (ramipril, captopril, fosinopril), reduce serum levels of CRP; while enalapril and trandolapril have not been shown to have the same effect. Angiotensin receptor blockers (ARBs) (valsartan, irbesartan, olmesartan, telmisartan) markedly reduce serum levels of CRP. The findings with other ARBs (losartan and candesartan) were inconsistent. Antidiabetic agents (rosiglitazone and pioglitazone) reduce CRP levels, while insulin is ineffective. Calcium channel antagonists have variable effects on CRP levels. Hydrochlorothiazide and oral estrogen do not affect CRP. The CRP-lowering effect of statins is more pronounced than their lipid lowering effect and is not dependent on their hypolipemic activity. The effect of atorvastatin on CRP seems to be dose-dependent. CRP-lowering effect of statins is likely to contribute to the favorable outcome of statin therapy. The data suggest that lipid lowering agents, ACE inhibitors, ARBs, antidiabetic agents, antiinflammatory and antiplatelet agents, vitamin E, and beta-adrenoreceptor antagonists lower serum or plasma levels of CRP, while vitamin C, oral estrogen and hydrochlorothiazide do not affect CRP levels.

Non-low-density lipoprotein cholesterol-associated actions of ezetimibe: an overview

Ezetimibe, an intestinal cholesterol absorption inhibitor, lowers circulating low-density lipoprotein cholesterol (LDL-C) levels both when administered as monotherapy and in combination with other hypolipidaemic drugs, mostly statins. This review focuses on the effects of ezetimibe on non-LDL-C-associated variables. In most studies, ezetimibe effectively reduced triglyceride and increased high density lipoprotein cholesterol levels. The authors also consider the effect of ezetimibe on other variables such as C-reactive protein levels, insulin sensitivity and endothelial function. Ezetimibe is useful in patients with sitosterolaemia (a rare inherited disorder) as it significantly reduces plasma phytosterol concentrations. Ezetimibe fulfils two of the three essential characteristics of any drug (efficacy and safety). However, clinical studies are required to provide evidence of its ability to reduce vascular events.

Cholesterol absorption inhibitors as a therapeutic option for hypercholesterolaemia

The development of cholesterol-lowering drugs (including a variety of statins, bile acid-binding resins and recently discovered inhibitors of cholesterol absorption) has expanded the options for cardiovascular prevention. Recent treatment guidelines emphasise that individuals at substantial risk for atherosclerotic coronary heart disease should meet defined targets for LDL cholesterol concentrations. Combination therapy with drugs that have different or complementary mechanisms of action is often needed to achieve lipid goals. Existing approaches to the treatment of hypercholesterolaemia are still ineffective in halting the progression of coronary artery disease in some patients despite combination therapies. Other patients are resistant to conventional drug treatment and remain at high risk for the development and progression of atherosclerotic cardiovascular disease and alternative approaches are needed. The discovery and development of ezetimibe (a novel, selective and potent cholesterol absorption inhibitor) has advanced the treatment of hypercholesterolaemia. New agents including the phytostanol preparation FM-VP4 and inhibitors of acyl coenzyme A:cholesterol acyltransferase, the apical Na(+)-dependent bile acid transporter and microsomal triglyceride transfer protein may also play a future role in combination therapy. This review focuses on the recent progress in the molecular mechanisms of intestinal cholesterol absorption and transport, and novel therapeutic approaches to inhibit the cholesterol absorption process.

Ezetimibe analogs with a reorganized azetidinone ring: Design, synthesis, and evaluation of cholesterol absorption inhibitions

The underlying principle of drug design in this paper is that the maximum retention of the functional groups that exist in the marketed drug would provide a higher probability for comparable safety while the conformational changes in the newly created analogs should not constitute a significant structural variation to adversely affect biological activity. Four individual isomers of backbone re-organized ezetimibe analogs were designed and synthesized. Their effects on the cholesterol levels in rat serum were evaluated by a high-cholesterol and high-fat diet feeding experiment. All the new analogs showed significant effect in lowering the levels of total cholesterol in serum.

Management of dyslipidemia in diabetes

Diabetes is associated with a high risk of cardiovascular disease. The management of dyslipidemia, a well-recognized and modifiable risk factor among patients with type 2 diabetes, is an important element in the multifactorial approach to prevent coronary heart disease. Diabetic dyslipidemia typically consists of elevated triglyceride, low high-density lipoprotein cholesterol (HDL-C), and the predominance of small dense low-density lipoprotein (LDL) particles. LDL cholesterol (LDL-C) levels in patients with diabetes are similar to those found in the rest of the population. During the past few years, clinical trials have provided evidence that lipid-lowering therapy has a similar beneficial effect on cardiovascular outcomes in diabetic and nondiabetic individuals. According to current guidelines, the primary lipid target is an LDL-C <100 mg/dL (<70 mg/dL in very high-risk patients) and, to this end, statins are the agents of choice. The appropriate management of dyslipidemia in patients with diabetes, particularly in individuals with low LDL-C, remains controversial. To achieve lipid targets, attention should be directed first toward nonpharmacologic therapeutic interventions to control dyslipidemia, such as diet, exercise, smoking cessation, weight loss, and glycemic control. Statin therapy is recommended for most subjects but, frequently, a combination of lipid-lowering agents is required. A number of combinations are possible, and several factors should be considered to improve the safety of this strategy.

In vivo responsiveness to ezetimibe correlates with niemann-pick C1 like-1 (NPC1L1) binding affinity: Comparison of multiple species NPC1L1 orthologs

Ezetimibe is the first in class 2-azetidinone that decreases plasma cholesterol by blocking intestinal cholesterol absorption. Ezetimibe effectively reduces plasma cholesterol in several species including human, monkey, dog, hamster, rat, and mouse, but the potency ranges widely. One potential factor responsible for this variation in responsiveness is diversity in ezetimibe metabolism. After oral administration, ezetimibe is glucuronidated. Both ezetimibe and the glucuronide lower plasma cholesterol; however, the glucuronide exhibits greater potency. Recent identification of Niemann-Pick C1 Like-1 (NPC1L1) as the molecular target of ezetimibe enables direct binding studies to be performed. Here, we report the cloning of NPC1L1 derived from multiple species and assess amino acid sequence homology among human, monkey, dog, hamster, rat, and mouse. The rank order of affinity of glucuronidated ezetimibe for NPC1L1 in each species correlates with the rank order of in vivo activity with monkey > dog > hamster and rat >> mouse. Ezetimibe analogs that bind to NPC1L1 exhibit in vivo cholesterol-lowering activity, whereas compounds that do not bind NPC1L1 are inactive. Specific structural components of ezetimibe are identified as critical for binding to NPC1L1. The results demonstrate that small variations in ezetimibe structure or in NPC1L1 amino acid sequence can profoundly influence ezetimibe/NPC1L1 interaction and consequently in vivo activity. The results demonstrate that the ability of compounds to bind to NPC1L1 is the major determinant of in vivo responsiveness.

Are lower levels of low-density lipoprotein cholesterol beneficial? A review of recent data

In the 1960s, epidemiologic studies established a link between elevated serum cholesterol and increased risk of cardiovascular events. Extensive clinical trial data subsequently highlighted 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (ie, statins) as the most effective pharmacotherapy for lowering low-density lipoprotein (LDL) cholesterol, and showed that statin-mediated LDL cholesterol reductions were associated with significant improvements in cardiovascular outcomes. Such findings are reflected in current cardiovascular disease management guidelines, which focus on LDL cholesterol as the primary therapeutic target. These guidelines recommend target LDL cholesterol levels. However, a number of clinical trials have failed to identify an LDL cholesterol threshold level below which no further cardiovascular risk reduction occurs. Such findings suggest that optimal risk reduction may require greater reductions in LDL cholesterol than are currently being achieved. This review examines recent data highlighting the benefits of more pronounced LDL cholesterol reductions and considers how this could be achieved in clinical practice when many patients are not even reaching current targets.

Effectiveness of ezetimibe added to ongoing statin therapy in modifying lipid profiles and low-density lipoprotein cholesterol goal attainment in patients of different races and ethnicities: a substudy of the Ezetimibe add-on to statin for effectiveness trial

OBJECTIVE

To examine whether the improvements in lipid profiles and low-density lipoprotein cholesterol (LDL-C) goal attainment found in the Ezetimibe Add-On to Statin for Effectiveness trial occurred equally in the black, Hispanic, and white patient populations enrolled in the study.

PATIENTS AND METHODS

In this double-blind, placebo-controlled study, patients were recruited from 299 community-based practices across the United States (January to August 2003). Patients with, hypercholesterolemia and LDL-C levels exceeding National Cholesterol Education Program Adult Treatment Panel III goals were randomized (2:1) to receive either ezetimibe (10 mg/d) or placebo in addition to their ongoing statin therapy for 6 weeks.

RESULTS

A total of 5802 patients were screened at baseline for the Ezetimibe Add-On to Statin for Effectiveness study. Of these, 2772 were excluded, and the remaining 3030 eligible patients were randomized. Ezetimibe, compared with placebo, added to statin therapy significantly reduced LDL-C levels from statin-treated baseline by 23.0% (white patients), 23.0% (black patients), and 21.0% (Hispanic patients). This effect was consistent across race and ethnicity groups (P > .50 for treatment-by-race interactions). Ezetimibe added to statin therapy also statistically significantly (P < .001) increased the percentage of patients attaining their LDL-C goal for their National Cholesterol Education Program Adult Treatment Panel III risk category in black (63.0%), Hispanic (64.8%), and white (72.3%) patients compared with placebo plus statin (32.9% black patients, 19.0% Hispanic patients, and 19.7% white patients). Ezetimibe treatment improved other lipid parameters across groups, including triglyceride, high-density lipoprotein cholesterol, non-high-density ilpoprotein cholesterol, and total cholesterol levels. Finally, the addition of ezetimibe reduced high-sensitivity C-reactive protein levels overall, and no significant interaction of treatment by race occurred (P = .83), Indicating a consistent effect across races. Ezetimibe was generally well tolerated, and no detectable differences occurred in the adverse event profile by race or ethnicity.

CONCLUSION

Ezetimibe added to statin therapy is effective and well tolerated for improving the lipid profile and LDL-C goal attainment of patients regardless of race or ethnicity.

Ezetimibe added to ongoing statin therapy improves LDL-C goal attainment and lipid profile in patients with diabetes or metabolic syndrome

This analysis of the Ezetimibe Add-on to Statin for Effectiveness (EASE) trial examined the effectiveness and safety of ezetimibe 10 mg added to ongoing statin therapy in patients with diabetes, metabolic syndrome without diabetes, or neither disorder who had low-density lipoprotein cholesterol (LDL-C) levels exceeding National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) goals. After six weeks of treatment, ezetimibe added to statin reduced LDL-C in patients with diabetes by 28%, metabolic syndrome by 24%, or neither by 26%, compared with a 3% reduction for placebo for each group. In each group, more patients receiving ezetimibe plus statin reached LDL-C goal (67-74%) compared with those receiving placebo plus statin (19-22%). Other parameters demonstrating greater improvement with ezetimibe included triglycerides, apolipoprotein (Apo)B/Apo A-I ratio, high-density lipoprotein cholesterol (HDL-C), and C-reactive protein. Ezetimibe plus statin was well tolerated in each group. Ezetimibe added to ongoing statin therapy offers a new treatment option that is consistently effective in improvement of lipid profiles and attainment of LDL-C goals in patients with without diabetes or metabolic syndrome.

The clinical effect and tolerability of ezetimibe in high-risk patients managed in a specialty cardiovascular risk reduction clinic

INTRODUCTION

Ezetimibe (EZ) is a selective cholesterol absorption inhibitor approved for use in Canada. The effect and tolerability of EZ among patients was evaluated in the clinical setting of a specialty cardiovascular risk reduction clinic at the University of Alberta Hospital, Edmonton, Alberta. patients and

METHODS

All patients 18 years of age or older who were prescribed EZ were included, unless they failed to take EZ for a minimum of two weeks, did not have baseline and on-EZ low-density lipoprotein cholesterol (LDL-C) levels, or had concomitant lipid-lowering drugs or dosages changed within one month of starting EZ.

RESULTS

Eighty-four patients (mean age 57.9 years) were included. By Framingham risk calculation, 71.4% were found to be high-risk patients, 13.1% moderate-risk patients and 15.5% low-risk patients; 66.7% of patients had prior cardiovascular events. On EZ, the mean reductions were: total cholesterol level 1.11 mmol/L (16.5%); LDL-C level 1.01 mmol/L (22.3%); high-density lipoprotein cholesterol level 0.06 mmol/L (4.6%); and ratio of total cholesterol level to high-density lipoprotein cholesterol level 0.68 mmol/L (12.8%); all were statistically significant (P<0.001). Results were similar when stratified by primary (n=28) versus secondary (n=56) prevention. Patients on EZ monotherapy (n=34) had mean LDL-C reductions of 1.03 mmol/L (20.5%) compared with 1.19 mmol/L (30.1%) or 0.95 mmol/L (22.5%), where EZ was added to low-dose or high-dose statins (P<0.01 for all). On EZ, 30 patients (35.7%) achieved previously unattainable target LDL-C levels. Four patients discontinued the drug due to side effects.

CONCLUSIONS

EZ is safe and effective in high-risk patients treated in the clinical setting of a cardiovascular risk reduction clinic. A mean LDL-C reduction of 1 mmol/L (20% to 30%) in all patient subgroups is consistent with previous clinical trial results. The significant reduction in LDL-C (mean 22.5%) observed in the EZ plus high-dose statin subgroup provides clinical evidence for use of this medication beyond published studies.

Premature cardiovascular disease in young women with heterozygous familial hypercholesterolemia

Heterozygous familial hypercholesterolemia is associated with elevated low-density lipoprotein cholesterol levels and the development of premature cardiovascular disease. Despite this general statement, data regarding the incidence of cardiovascular disease in young women with familial hypercholesterolemia are lacking. In this review, information of age-specific incidence, risk factors and therapeutic avenues in women with heterozygous familial hypercholesterolemia are discussed.

Combination of statin and ezetimibe for the treatment of dyslipidemias and the prevention of coronary artery disease

The prevention of coronary artery disease (CAD) involves therapeutic lifestyle changes such as smoking cessation, diet, weight reduction and exercise. In patients with established CAD or atherosclerosis in other vascular beds, or in patients at high risk of developing CAD, lowering serum total and low-density lipoprotein cholesterol (LDL-C) has been associated with a reduction in cardiovascular morbidity and mortality, and total mortality. Recently, large-scale studies have shown that lowering the LDL-C to less than 2.0 mmol/L is associated with a reduction of major cardiac events in patients with established CAD. Therapy with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has had a major impact on preventive cardiology. Not all patients reach recommended LDL-C targets on currently available statins. Ezetimibe is a selective inhibitor of intestinal cholesterol absorption that results in an additional 15% to 25% reduction of LDL-C. The recommended dosage is 10 mg once daily; it is safe and well tolerated. Elevations in transaminase and creatine kinase occur in approximately 1% of subjects. Ezetimibe is suggested for patients who do not reach recommended LDL-C targets on an optimal dosage of statins alone. While the effects of ezetimibe on atherosclerosis have not been ascertained, clinical trials have consistently shown that the reduction in serum cholesterol correlates with a decrease in major cardiovascular events, irrespective of the method used to reduce cholesterol.