冠心病调脂治疗靶点研究

目的:探讨冠心病调脂治疗靶点.方法:R型聚类分析低密度脂蛋白胆固醇(LDL-C)等9个血脂评价指标的代表指标.回顾性病例对照研究他汀治疗(119例)与非他汀治疗(108例)两组冠心病患者ApoA1/ApoB、non-HDL-C、LDL-C判定的血脂达标率,达标和不达标者病情进展率及急性冠脉综合征(ACS)发生比值比.结果:9个指标聚为二类,代表指标为non-HDL-C、ApoA1/ApoB.3个指标评价他汀组血脂达标率分别为35.3％(42/119)、33.6％(40/119)和27.7％(33/119),非他汀组不达标率分别为86.1％(93/108)、90.7％(98/108)和95.4％(103/108).他汀组不达标者病情进展率分别显著低于非他汀组不达标者(x2分别为21.75、30.19、23.32,P均为0.001).他汀组non-HDL-C的ACS发生比值与ApoA1/ApoB、LDL-C的ACS发生比值比在0.8～1.2范围之外,ApoA1/ApoB与LDL-C的ACS发生比值比及非他汀组三指标评价不达标者ACS发生比值比在0.8～1.2.结论:提高冠心病患者他汀治疗率显著降低冠心病患者ACS发生率.调脂治疗靶点不同,冠心病例ACS发生几率有差异,调脂治疗靶点值得研究.ApoA1/ApoB、LDL-C作为调脂治疗靶点作用相近.     

What future for combination therapies?

For most patients who require lipid-lowering treatment, statin monotherapy is the appropriate treatment. However, in those patients where statin monotherapy does not produce optimal lipid levels, the combination of a statin with niacin, a bile acid sequestrant, a fibric acid derivative, a cholesterol absorption inhibitor or a fish oil preparation may provide improved control. The choice of combination therapy depends upon the patient's lipid profile and tolerability of the medication. Combination of a statin with niacin, a bile acid sequestrant or ezetimibe, a cholesterol absorption inhibitor, should be considered for patients with very high low-density lipoprotein cholesterol (LDL-C) levels, while combination with either a fibric acid derivative or a fish oil should be considered for patients with high LDL-C and high triglyceride levels. A number of new lipid-lowering agents are currently in development, including cholesteryl ester transfer protein (CETP) inhibitors, acyl coenzyme A: cholesterol acyltransferase (ACAT) inhibitors, ileal bile acid transport (IBAT) inhibitors, microsomal triglyceride transfer protein (MTP) inhibitors and dual peroxisome proliferator-activated receptor (PPAR) alpha and gamma agonists. Introduction of these novel therapies will provide opportunities for developing different combination strategies that may help to optimise lipid profiles in patients who are currently difficult to treat. The introduction of new combinations will require careful study to ensure that the risks of drug interactions and adverse events are minimised.     

Estimating the health benefits and costs associated with ezetimibe coadministered with statin therapy compared with higher dose statin monotherapy in patients with established cardiovascular disease: results of a Markov model for UK costs using data registries

BACKGROUND: Ezetimibe has been reported to improve lipid control in patients with established cardiovascular disease (CVD). OBJECTIVE: The aim of this study was to estimate the potential long-term impact on health status of prescribing ezetimibe in combination with statin therapy in patients with established CVD and evaluate its cost-effectiveness in a health economic model. METHODS: A Markov model was used to compare ezetimibe and statin combination therapy with statin monotherapy. A published relationship linking changes in low-density lipoprotein cholesterol and cardiovascular events was used to estimate the cardiovascular events avoided through lipid-lowering therapies. The model was populated using results of extensive literature searches and a meta-analysis of clinical evidence. An adjustment was applied to model second-line lipid-lowering benefits. Conservative assumptions were used to extend the patient pathway beyond the clinical evidence. The analysis took the perspective of the UK Department of Health; therefore, only direct costs were included. Costs were calculated as year-2006 British pounds. RESULTS: For a cohort of 1,000 hypothetical male patients aged 55 years, ezetimibe coadministered with current statin therapy was estimated to prevent a mean of 43 nonfatal myocardial infarctions, 7 nonfatal strokes, and 26 cardiovascular deaths over a lifetime, compared with doubling the current statin dose. The events avoided would provide a mean of 134 additional quality-adjusted life-years (QALYs). With a mean incremental cost of pound 3,693,000, the lifetime discounted cost per QALY gained would be pound 27,475 (95% CI, pound 27,331- pound 27,620) and would rise to pound 32,000 for men aged 75 years. CONCLUSIONS: The results suggest that, in some instances, ezetimibe coadministration may be cost-effective compared with statin monotherapy, but there are several limitations with this model. The economic effects of ezetimibe must be revisited when long-term effectiveness and safety data become available.     

Supratherapeutic response to ezetimibe administered with cyclosporine

OBJECTIVE: To report the case of a patient who underwent orthotopic heart transplant (OHT) and demonstrated a supratherapeutic response to ezetimibe when administered with cyclosporine. CASE SUMMARY: Ezetimibe 10 mg/day was added to the lipid-lowering regimen (atorvastatin 40 mg/day) of a 64-year-old male patient after OHT to achieve a target low-density lipoprotein cholesterol (LDL-C) level < or = 97 mg/dL, as recommended by national guidelines. After 2 months of ezetimibe, the patient's LDL-C level had decreased by 60% to 51 mg/dL. Subsequently, the dose of ezetimibe was reduced to 5 mg/day and, after another 2 months, a repeat lipid panel revealed LDL-C 57 mg/dL. DISCUSSION: Hyperlipidemia is a common problem among heart transplant recipients. Combination therapy using a statin plus ezetimibe appears to be an attractive option to achieve target lipid levels in this population. However, the manufacturer warns that ezetimibe should be administered cautiously in patients concomitantly receiving cyclosporine. Unpublished data suggest a pharmacokinetic interaction between ezetimibe and cyclosporine that results in a significant 2.3- to 12-fold increase in exposure to total ezetimibe. An objective causality assessment in this case revealed that this supratherapeutic LDL-C reduction was probably related to coadministration of ezetimibe and cyclosporine. A potential mechanism to explain this interaction might be an alteration in glucuronidation induced by cyclosporine. CONCLUSIONS: When ezetimibe is prescribed for patients concomitantly receiving cyclosporine, it should be initiated at a lower than recommended dose (> or = 5 mg/day) and titrated upward. Careful and consistent monitoring of patients on this combination is also advised.     

A community-based, randomized trial of ezetimibe added to statin therapy to attain NCEP ATP III goals for LDL cholesterol in hypercholesterolemic patients: the ezetimibe add-on to statin for effectiveness (EASE) trial

OBJECTIVE: To determine the extent of reduction in low-density lipoprotein cholesterol (LDL-C) level and improvement in National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) LDL-C goal attainment when ezetimibe was added to ongoing statin therapy in a diverse population of community-based patients. PATIENTS AND METHODS: In this multicenter, double-blind, placebo-controlled trial (from January 2003 to August 2003), hypercholesterolemic patients (from 299 US primary care and specialty practices) with LDL-C levels exceeding NCEP ATP III goals were randomized (2:1) to receive ezetimibe (10 mg/d) or placebo in addition to their ongoing statin therapy for 6 weeks. RESULTS: In a study of 3030 randomized patients, ezetimibe added to statin therapy significantly reduced the LDL-C level by an additional 25.8% in the total population, compared with an additional 2.7% reduction with placebo plus statin (treatment difference, -23.1%; P<.001); the treatment difference ranged from -19.9% to -24.0% (P<.001) in each NCEP ATP III risk category subgroup. Significantly (P<.001) more patients (71.0%) treated with ezetimibe added to statin reached their NCEP ATP III target LDL-C level compared with those treated with placebo plus statin (20.6%). The addition of ezetimibe also resulted in improvement in other lipid parameters and high-sensitivity C-reactive protein levels. These benefits were consistent across sex, race, age, statin brand, and dose subgroups. Ezetimibe plus statin therapy was well tolerated, with a safety profile similar to placebo plus statin. CONCLUSION: Across multiple subgroups, ezetimibe added to statin therapy consistently produced significant additional improvements in LDL-C levels and goal attainment, as well as in other lipoproteins, compared with addition of placebo. The addition of ezetimibe to statin therapy should be considered for patients not achieving their NCEP ATP III LDL-C goals while receiving statin therapy alone.     

PCSK9 inhibitors: a non-statin cholesterol-lowering treatment option

Elevated low-density lipoprotein cholesterol (LDL-C) plays a major role in the development of atherosclerotic cardiovascular disease. Statins are the first-line treatment to lower LDL-C in patients with hypercholesterolemia; however, some high cardiovascular risk patients may have inadequate responses to statin therapy or are intolerant to statins, and may need additional and/or alternative non-statin therapies to further reduce their LDL-C levels. Monoclonal antibodies that inhibit proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of circulating LDL-C levels, have received considerable attention as promising non-statin therapeutic options for the management of hypercholesterolemia. This review provides a brief overview of the history and science of PCSK9 inhibitors, focusing on two PCSK9 monoclonal antibodies that have been approved by the US Food and Drug Administration: alirocumab and evolocumab. Recently released and forthcoming clinical trial data will be discussed, as well as the practical application of patient populations that may benefit from PCSK9 inhibitors. Finally, the recent expert recommendations regarding the use of PCSK9 inhibitors and other non-statin therapies to treat patients with inadequate LDL-C-lowering on statin therapy will be summarized.     

Ezetimibe: a novel option for lowering cholesterol

Elevated low-density lipoprotein (LDL)-cholesterol is associated with a significantly increased risk of coronary heart disease but lowering LDL-cholesterol to levels established in current National Cholesterol Education Program (NCEP) guidelines provides significant risk reduction. Nevertheless, many patients receiving lipid-lowering therapy, particularly those at highest coronary heart disease risk, do not reach LDL-cholesterol goals with their current medications. Ezetimibe (Zetia^®, Merck Schering-Plough) is the first of a new class of lipid-lowering drugs known as cholesterol absorption inhibitors. Ezetimibe has a favorable pharmacokinetic profile, which allows it to be administered once daily and to be given in conjunction with statins. In a series of randomized, controlled, multicenter studies, ezetimibe produced significant improvements in levels of LDL-cholesterol and other lipid parameters when used as monotherapy, with a safety profile comparable with that of placebo. Furthermore, coadministration of ezetimibe with a statin (simvastatin, atorvastatin, lovastatin, or pravastatin) was more effective than statin monotherapy in lowering LDL-cholesterol and improving other lipid parameters. Moreover, coadministration of ezetimibe with a statin allowed a greater percentage of patients to achieve treatment goals established in NCEP guidelines. The safety and side-effect profile of ezetimibe plus statin coadministration therapy was generally comparable with that of statin monotherapy. These studies establish ezetimibe as an effective lipid-lowering agent, which will likely be useful in the management of a broad range of patients with hypercholesterolemia. Ezetimibe can be used in conjunction with a statin at the beginning of therapy, or it can be added if patients do not achieve their LDL-cholesterol goal with statins alone.     

Total and low-density lipoprotein cholesterol responses to ezetimibe in clinical practice

Clinical trials have shown that ezetimibe significantly improves lipid profiles when used as monotherapy or in combination with a statin or fibrate. To assess its effect in clinical practice, a retrospective audit of changes in total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) was conducted in 180 hospital outpatients (mean age 57 years, 58% male) who received ezetimibe for at least 4 weeks. When added to existing therapy, (n = 164) mean reductions in TC and LDLC were 19 and 26%, respectively, larger falls occurring in those already on a statin than when on a fibrate or when used as monotherapy. Bigger mean reductions in TC and LDLC (25 and 36%, respectively) were seen in patients already on a statin and fibrate where ezetimibe replaced the fibrate (n = 16). There were a large range of TC and LDLC responses in each treatment group which are likely to relate, at least in part, to individual variability in cholesterol absorption. As expected from the improvement in TC and LDLC, more patients achieved recognised cholesterol targets after ezetimibe use. The response to ezetimibe in routine practice appears to be consistent with that seen in clinical trials.     

Ezetimibe: a novel option for lowering cholesterol

Elevated low-density lipoprotein (LDL)-cholesterol is associated with a significantly increased risk of coronary heart disease but lowering LDL-cholesterol to levels established in current National Cholesterol Education Program (NCEP) guidelines provides significant risk reduction. Nevertheless, many patients receiving lipid-lowering therapy, particularly those at highest coronary heart disease risk, do not reach LDL-cholesterol goals with their current medications. Ezetimibe (Zetia, Merck Schering-Plough) is the first of a new class of lipid-lowering drugs known as cholesterol absorption inhibitors. Ezetimibe has a favorable pharmacokinetic profile, which allows it to be administered once daily and to be given in conjunction with statins. In a series of randomized, controlled, multicenter studies, ezetimibe produced significant improvements in levels of LDL-cholesterol and other lipid parameters when used as monotherapy, with a safety profile comparable with that of placebo. Furthermore, coadministration of ezetimibe with a statin (simvastatin, atorvastatin, lovastatin, or pravastatin) was more effective than statin monotherapy in lowering LDL-cholesterol and improving other lipid parameters. Moreover, coadministration of ezetimibe with a statin allowed a greater percentage of patients to achieve treatment goals established in NCEP guidelines. The safety and side-effect profile of ezetimibe plus statin coadministration therapy was generally comparable with that of statin monotherapy. These studies establish ezetimibe as an effective lipid-lowering agent, which will likely be useful in the management of a broad range of patients with hypercholesterolemia. Ezetimibe can be used in conjunction with a statin at the beginning of therapy, or it can be added if patients do not achieve their LDL-cholesterol goal with statins alone.     

Cross-Sectional Survey to Assess the Status of Lipid Management in High-Risk Patients With Dyslipidemia: Clinical Impact of Combination Therapy With Ezetimibe

BackgroundPrevious retrospective surveys have shown that lipid management goals are well achieved in patients with dyslipidemia at relatively low risk for atherosclerotic diseases. However, more than half of patients in high-risk groups have not achieved the management goals. Since these surveys, newer medications, including rosuvastatin and ezetimibe, have emerged in clinical practice that may influence lipid management.ObjectiveTo assess the current status of lipid management in high-risk patients, we conducted a cross-sectional study between January and March 2010.MethodsEligible patients were those with dyslipidemia who were classified into the primary prevention high-risk or secondary prevention groups according to the Japan Atherosclerosis Society guideline for diagnosis and prevention of atherosclerotic cardiovascular diseases. Patient data were collected from 300 randomly selected physicians at hospitals and clinics across Japan if patients had been receiving the same statin with or without other lipid-lowering agents for ≥3 months. The main outcome was the percentage of patients who achieved the serum LDL-C goal according to the guideline.ResultsData were collected from 1720 patients. The LDL-C goal was achieved in 56.5% of patients (447 of 791) in the primary prevention high-risk group and in 24.5% (103 of 420) in the secondary prevention group by statin monotherapy. For patients who had not reached the LDL-C goal with statin therapy alone, 53.8% (113 of 210) in the primary prevention high-risk group and 63.8% (111 of 174) in the secondary prevention group achieved their lipid management goal with the addition of ezetimibe. Ezetimibe significantly lowered mean serum LDL-C levels by 17.9% to 34.6% when added to various statins (P < 0.001).ConclusionsAlthough strong statins are available, lipid management in high-risk patients remains unsatisfactory. More aggressive treatment is needed for these patients.     

Ezetimibe for management of hypercholesterolemia

OBJECTIVE: To review the primary literature describing the pharmacology of ezetimibe and clinical trials investigating its use in the management of hypercholesterolemia. DATA SOURCES: A MEDLINE search (1966-December 2002) was performed using SCH 48461, SCH 58235, ezetimibe, and 2-azetidinone as key words. English-language articles were identified and the references of these articles were used to further identify pertinent articles and abstracts. Given the paucity of published articles available on ezetimibe, many of the references cited are abstracts. STUDY SELECTION: All acquired articles that discussed the pharmacology, pharmacokinetics, chemistry, and clinical efficacy of ezetimibe were reviewed. DATA EXTRACTION: Articles were selected based on content regarding the medicinal chemistry, pharmacology, and clinical use of ezetimibe. DATA SYNTHESIS: Ezetimibe, approved for use in October 2002, belongs to a new class of antihyperlipidemic agents that uniquely inhibit the absorption of cholesterol by inhibiting the cholesterol transport system located within intestinal cell walls. In humans, ezetimibe reduced cholesterol absorption by >50%. In clinical trials, ezetimibe 10 mg/d reduced low-density lipoprotein cholesterol (LDL-C) by approximately 18% and further enhanced the LDL-C-lowering effect of statin medications by an additional 15-20%. In addition, ezetimibe lowered triglycerides about 5% and increased high-density lipoprotein cholesterol (HDL-C) approximately 3%. Ezetimibe is well tolerated. At present, no serious adverse effects have been directly attributable to ezetimibe. CONCLUSIONS: Based on the data currently available, it appears that ezetimibe has a potential role in the treatment of primary hypercholesterolemia; however further data are needed to determine its long-term tolerability and efficacy. The potential roles for ezetimibe include its concurrent use with a statin to further enhance the lowering of LDL-C. Other possible roles for ezetimibe include its concurrent use with a statin to permit a lowering of statin dosage to avoid statin-related complications or its use as monotherapy to treat hypercholesterolemia when statin use cannot be tolerated or is contraindicated. Outcome data demonstrating that cardiovascular morbidity and/or mortality are reduced by ezetimibe therapy have yet to be generated.     

Effect of atorvastatin monotherapy and low-dose atorvastatin/ezetimibe combination on fasting and postprandial triglycerides in combined hyperlipedemia

Postprandial triglyceride (TG) levels are easy to measure and are associated with future cardiovascular risk. The aim of this study was to compare the effects of statin monotherapy and low-dose statin/ezetimibe on lipid parameters including fasting and postprandial TG. After a 4-week dietary run-in period, 78 patients with combined hyperlipidemia were randomized into 1 of 2 treatment groups for 8 weeks: atorvastatin 20 mg or atorvastatin/ezetimibe 5 mg/5 mg. An oral fat load test was performed before and after the drug-treatment period. The low-dose combination had a tendency to decrease fasting TG more than atorvastatin monotherapy. The combination regimen showed a greater reduction in postprandial TG (-13% ± 42% and -34% ± 30%, in the atorvastatin and combination groups, respectively, P = .03) and total cholesterol (TC; P = .03). The changes in low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) were not different between the 2 groups. The reduction in apo B/A1 was greater in the combination group (-32% ± 19% and -42% ± 13%, in the atorvastatin and combination groups, respectively, P = .02). In conclusion, these results demonstrated a potential beneficial effect of low-dose atorvastatin/ezetimibe combination treatment on postprandial TG control after comparable LDL-C lowering in patients with combined hyperlipidemia.     

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.     

Effects of fluvastatin extended-release (80 mg) alone and in combination with ezetimibe (10 mg) on low-density lipoprotein cholesterol and inflammatory parameters in patients with primary hypercholesterolemia: a 12-week, multicenter, randomized, open-label, parallel-group study

Background: Combining lipid-lowering agents with complementary mechanisms of action can provide greater cholesterol reductions than using either agent alone, improving achievement of target low-density lipoprotein cholesterol (LDL-C) levels. Objectives: The aim of this study was to assess the effects of fluvastatin extended-release (XL) 80 mg/d administered alone or combined with ezetimibe 10 mg/d on plasma lipid levels and inflammatory parameters in patients with primary hypercholesterolemia. The tol-erability of both regimens was also evaluated. Methods: In this multicenter, randomized, open-label, parallel-group study, patients with hypercholesterolemia were randomized in a 1:1 ratio to receive fluvastatin XL 80 mg/d alone or in combination with ezetimibe 10 mg/d for 12 weeks. The primary end point was the percentage change from baseline to week 12 in LDL-C level with fluvastatin XL + ezetimibe combination therapy compared with fluvastatin XL alone. Plasma concentrations of inflammatory biomarkers were measured at baseline and week 12. Proportions of patients who achieved National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) LDL-C goals were calculated. Tolerability was assessed by the monitoring and recording of all adverse events (AEs) and laboratory values. Results: A total of 82 patients were enrolled (mean [SD] age, 50.0 [12.0] years; 44% male; 100% white; mean [SD] weight, 73.5 [14.9] kg; combination group, 38 patients; monotherapy group, 44). Fluvastatin XL + ezetimibe and fluvastatin XL monotherapy were associated with significant decreases from baseline in mean LDL-C level (by 49.9% and 35.2%, respectively; between-group difference, P < 0.001). Fluvastatin XL + ezetimibe was associated with significantly greater reductions from baseline than fluvastatin XL monotherapy in total cholesterol (38.2% vs 27.5% P < 0.001), triglycerides (21% vs 3.8% P = 0.02) and apolipoprotein B (34.8% vs 22.5% P < 0.001). NCEP ATP III LDL-C goals were achieved by 87% of patients receiving fluvastatin XL + ezetimibe and 67% of patients receiving fluvastatin XL monotherapy (between-group difference, P = 0.042). The combination was associated with significantly lowered high-sensitivity C-reactive protein (hs-CRP) levels in patients with high baseline hs-CRP (>2 mg/L; P < 0.02), >1 cardiovascular risk factor (P < 0.05), or hypertension (P = 0.015); both regimens were associated with significantly reduced plasma levels of interleukin-1B. No significant between-group differences in the incidences of AEs were found. Most AEs were mild or moderate in intensity. Headache was the most common AE, occurring in 5/44 (11.4%) patients in the fluvastatin XL group and 2/38 (5.3%) patients in the fluvastatin XL + ezetimibe group. One serious AE (convulsive crisis) occurred in a patient receiving fluvastatin XL + ezetimibe, but was not suspected to be related to study medication. Conclusion: Fluvastatin XL in combination with ezetimibe was found to be well-tolerated and effective, allowing the majority (87%) of these patients with primary hypercholesterolemia to achieve current treatment goals, and reduced hs-CRP levels in patients at higher cardiovascular risk.     

Ezetimibe in hypercholesterolaemia

Ezetimibe is the first member of a new class of selective cholesterol absorption inhibitors, compounds that effectively block intestinal absorption of dietary and biliary cholesterol, without affecting absorption of fat soluble vitamins or triglycerides. Ezetimibe underwent glucuronidation to a single metabolite and localised at the intestinal wall, where it prevented luminal cholesterol absorption. Pre-clinical studies demonstrated the lipid-lowering and antiatherosclerotic properties of ezetimibe. The efficacy and safety of ezetimibe monotherapy have been determined in phase II/III studies: in phase II studies, the optimal efficacy was reached with ezetimibe 10 mg per day and the pooled efficacy data have shown that ezetimibe 10 mg has a positive effect on the lipoprotein profile with a significant reduction in LDL-cholesterol of 18.5%, an increase in HDL-cholesterol of 3.5% and a trend towards lowering in triglyceride concentrations (-4.9%). The monotherapy phase III studies have confirmed the efficacy with a decrease in LDL-C of 17.4% and have demonstrated an excellent safety and tolerability profile. The potential for a pharmacokinetic and/or pharmacodynamic interaction between ezetimibe and various statins and the efficacy and safety or the co-administration of ezetimibe and statins have been evaluated in different phase I/II studies: ezetimibe had no significant effect on the pharmacokinetics of simvastatin or atorvastatin. Ezetimibe 10 mg co-administrated with the starting dose of any statin induced a mean 18% additive LDL-C lowering effect. This additive 18% reduction in LDL-C is achieved in one step compared with the three steps necessary with statin monotherapy.     

Effects of ezetimibe/simvastatin on lipoprotein subfractions in patients with primary hypercholesterolemia: an exploratory analysis of archived samples using two commercially available techniques

BACKGROUND: Cholesterol-rich lipoproteins, including low-density lipoprotein cholesterol (LDL-C), intermediate-density lipoprotein cholesterol (IDL-C), and very-low-density lipoprotein cholesterol (VLDL-C), are known to promote atherosclerosis. Ezetimibe/simvastatin (E/S) is an efficacious lipid-lowering treatment that inhibits both the intestinal absorption and biosynthesis of cholesterol. OBJECTIVE: The aim of the current analysis was to compare the effects of ezetimibe and simvastatin monotherapy and E/S treatment on lipoprotein subfractions and LDL particle size in patients with primary hypercholesterolemia. METHODS: This was an exploratory (hypothesis generating) analysis of archived plasma samples drawn from patients in a multicenter, randomized, double-blind, placebo-controlled, parallel-arm study. After a washout and diet/placebo run-in, patients with hypercholesterolemia (LDL-C, > or =145- < or =250 mg/dL; triglycerides, < or =350 mg/dL) were randomized equally to 1 of 10 daily treatments for 12 weeks: E/S (10/10, 10/20, 10/40, or 10/80 mg), simvastatin monotherapy (10, 20, 40, or 80 mg), ezetimibe monotherapy (10 mg), or placebo. A subset of patients had lipid subfraction measurements taken at baseline (week 0) and postrandomization (week 12). Plasma samples were used to quantify cholesterol associated with VLDL subfractions (VLDLI+2 and VLDL3), IDL, and 4 LDL subfractions (LDL1-4) via the Vertical Auto Profile II method. LDL-C particle size was determined using segmented gradient gel electrophoresis. The primary end point was median percent change in subfraction cholesterol for E/S versus ezetimibe or simvastatin monotherapy, pooled across doses. RESULTS: Of the 1528 patients randomized in the original study, 1397 (91%) had lipid subfraction measurements taken. E/S was associated with significant reductions in VLDL-CI+2, VLDL-C3, IDL-C, LDL-C1, LDL-C2, and LDL-C3 versus ezetimibe, simvastatin, and placebo. E/S resulted in near-additive reductions in VLDL-CI+2, VLDL-C3, IDL-C, LDL-C1, LDL-C2, and LDL-C3 versus ezetimibe and simvastatin monotherapy. Of the subfractions examined, with regard to E/S, the greatest reductions were observed in IDL-C and LDL-C1, LDL-C2, and LDL-C3. When compared with placebo, ezetimibe, simvastatin, and E/S did not shift the distribution of LDL particles toward a larger, more buoyant LDL subclass pattern. CONCLUSION: E/S was more effective than ezetimibe and simvastatin monotherapy in reducing atherogenic lipoprotein subfractions in these patients with primary hypercholesterolemia.     

Pharmacology and therapeutics of ezetimibe (SCH 58235), a cholesterol-absorption inhibitor

BACKGROUND: Ezetimibe is the first of a new class of antihyperlipidemic agents, the cholesterol-absorption inhibitors. It is indicated for monotherapy or in combination with 3-hydroxy-3-methylglutaryl coenzyme A-reductase inhibitors (statins) in patients with primary hypercholesterolemia, in combination with simvastatin or atorvastatin in patients with homozygous familial hypercholesterolemia, and as monotherapy in patients with homozygous familial sitosterolemia. OBJECTIVE: This article reviews available data on the clinical pharmacology, clinical efficacy, and tolerability of ezetimibe. METHODS: A literature review was conducted using the search terms ezetimibe and SCH 58235 to identify articles and abstracts indexed in MEDLINE and the Iowa Drug Information Service from 1966 to February 2003. The reference lists of the identified articles were reviewed for additional publications. RESULTS: In adults, ezetimibe 10 mg PO given once daily has been reported to reduce intestinal cholesterol absorption by 54% from baseline in association with a compensatory increase in endogenous cholesterol synthesis. Within 2 weeks of its initiation, ezetimibe monotherapy produced a 17% to 20% reduction from baseline in low-density lipoprotein cholesterol (LDL-C); in combination with statins, ezetimibe produced a reduction in LDL-C of up to 40% over the same period. Based on studies performed to date, ezetimibe appears to be well tolerated, with a safety profile similar to that of placebo. Because ezetimibe is eliminated primarily by glucuronidation and not by cytochrome P450 (CYP) oxidation, it is subject to minimal drug interactions involving the CYP enzyme system. CONCLUSIONS: Ezetimibe is an option for monotherapy in patients with mild hypercholesterolemia or in those requiring adjunctive drug therapy for reduction of LDL-C levels. It may be useful in patients at risk for adverse events (eg, liver toxicity, myopathy) from other hypocholesterolemic agents. Additive LDL-C-lowering effects of ezetimibe may allow use of lower doses of conventional agents (eg, statins, fibric acid derivatives, niacin) to achieve an equivalent effect, thereby reducing the potential for adverse events and drug interactions. However, because trials have lasted no longer than 12 weeks, the long-term effect of ezetimibe on cardiovascular morbidity and mortality remains to be determined.     

Efficacy and safety of ezetimibe coadministered with statins: randomised, placebo-controlled, blinded experience in 2382 patients with primary hypercholesterolemia

We assessed pooled safety and lipid-regulating efficacy data from four similarly designed trials of ezetimibe coadministered with statins in 2382 patients with primary hypercholesterolemia. Patients were randomised to one of the following double-blind treatments for 12 weeks: placebo; ezetimibe 10 mg; statin; or statin + ezetimibe. Statin doses tested were 10, 20, 40 mg/day (atorvastatin, simvastatin, pravastatin or lovastatin) or 80 mg/day (atorvastatin, simvastatin). Treatment with ezetimibe + statin led to significantly greater reductions in low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B and increases in HDL-C, compared to statin alone. At each statin dose, treatment with ezetimibe + statin led to a greater LDL-C reduction compared to the next highest statin monotherapy dose. Ezetimibe + statin had a safety profile similar to statin monotherapy. Coadministration of ezetimibe + statin offers a well-tolerated, highly efficacious new treatment strategy for patients with hypercholesterolemia.     

Colesevelam HCl and ezetimibe combination therapy provides effective lipid-lowering in difficult-to-treat patients with hypercholesterolemia

This study investigated the effects of colesevelam hydrochloride (WelChol; Sankyo Pharma, Parsippany, NJ) and ezetimibe (Zetia; Merck/Schering Plough Pharmaceuticals, North Wales, PA), alone and in combination, for the treatment of hypercholesterolemia in patients who were intolerant to, or refused, HMG-Co-A reductase inhibitor (statin) therapy. Combination therapy with colesevelam HCl/ezetimibe resulted in an additional reduction in low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (HDL-C) levels of approximately 20% (P < 0.005) and 16% (P < 0.01), respectively, compared with monotherapy with either agent. Total cholesterol, LDL-C, and non-HDL-C levels were within National Cholesterol Education Program Adult Treatment Panel III target ranges at the end of the combination therapy regimen in 10 of 12 patients. In conclusion, colesevelam HCl/ezetimibe combination therapy appears to be an efficacious and well-tolerated alternative for patients with hypercholesterolemia.     

Coronary atherosclerosis can regress with very intensive statin therapy

The ASTEROID trial (JAMA 2006; 295:1556-1565) showed that very intensive statin therapy with rosuvastatin 40 mg once daily results in highly significant regression of coronary atherosclerosis as assessed by serial intravascular ultrasonography (IVUS). The mean low-density lipoprotein cholesterol (LDL-C) level achieved with this regimen was 61 mg/dL, and the mean high-density lipoprotein cholesterol (HDL-C) level increased by 15%. While the merits of concomitant LDL-C-lowering and HDL-C-raising therapies remain to be determined, the results of the ASTEROID and other recent trials suggest that the optimal strategy for lipid-lowering in patients with coronary artery disease is to try for the lowest LDL-C level that can be attained without adverse effects.