Drug treatment of lipid disorders

Statins for children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is one of the most common inherited metabolic diseases; the average worldwide prevalence of heterozygous familial hypercholesterolemia is about 1 in 500. Diagnosis of familial hypercholesterolemia in children is based on two measurements of low-density lipoprotein cholesterol level above 4.0 mmol/L or a DNA-based analysis. Coronary stenosis has been detected in men with familial hypercholesterolemia as young as 17 years old and in women with familial hypercholesterolemia at 25 years old. Atherosclerosis and its clinical complications occur prematurely, especially in men, thus lifelong hypolipidemic measures, started in childhood, are needed to reduce the risk of cardiovascular diseases. In children with familial hypercholesterolemia children, so far diet has been the main mode of treatment. Anion exchange resins, such as cholestyramine and colestipol, have also been found to be effective but are generally considered unpalatable and therefore poorly tolerated. Since the 1990s statin trials have been carried out among children with familial hypercholesterolemia (aged 7 to 17 years), and statins reduced their serum low-density lipoprotein cholesterol levels by 23% to 40%. The safety of statins among children is not well known even though statins seem to be safe and well-tolerated in adults.

OBJECTIVES

To assess the effectiveness and safety of statins in children with familial hypercholesterolemia.

SEARCH STRATEGY

Relevant trials were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline.Date of most recent search: 11 March 2010.

SELECTION CRITERIA

Randomized and controlled clinical trials including participants up to 18 years old comparing a statin to placebo or to diet alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

We found 19 potentially eligible studies of which we included eight randomized placebo-controlled trials (897 participants). Statins reduced the mean low-density lipoprotein cholesterol concentration at all time points. There was no difference between serum aspartate and alanine aminotransferase as well as creatine kinase concentrations at any time-point. The risks of myopathy and clinical adverse events were also similar in both groups. In one study simvastatin was shown to improve flow-mediated dilation of the brachial artery.

AUTHORS' CONCLUSIONS

Statin treatment is an efficient lipid-lowering therapy in children with familial hypercholesterolemia. It seems to be safe in the short term but long-term safety is unknown. Children treated with statins should be carefully followed up by their pediatricians. Large long-term randomized controlled trials are needed to establish the long-term safety of statins.

High density lipoproteins-based therapies for cardiovascular disease

Atherosclerosis is the leading cause of death in developed countries. High density lipoproteins (HDL) cholesterol level correlates inversely with the risk of cardiovascular diseases. Thus, HDL has obtained lots of interest for drug development. In this review, we summarized the mechanisms for the antiatherogenic function of HDL, current HDL-based drugs in clinical use and the future direction for HDL-based therapy development.

HDL-C and LDL-C: their role in stroke pathogenesis and implications for treatment

Elevated serum low-density lipoprotein cholesterol (LDL-C) and low serum high-density lipoprotein cholesterol (HDL-C) are risk factors for atherosclerotic ischemic stroke. The National Cholesterol Education Panel and the American Heart Association have released guidelines for the treatment of dyslipidemia that stress LDL-C reduction using HMG CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase inhibitors (statins) and are applicable to individuals who have had or are at a high risk of having a stroke. Treatment of low HDL-C is a secondary goal of these guidelines and can be best achieved by using extended-release niacin (alone or in combination with statins) and fibrates. Early and aggressive treatment of dyslipidemia is an important component of a multimodality approach to stroke prevention.

Prevalence and overlap of different lipid abnormalities in statin-treated patients at high cardiovascular risk in clinical practice in Germany

Background

In line with current guideline recommendations, patients at high cardiovascular risk are usually treated with statins for secondary as well as for primary prevention. While many studies investigated treatment goal achievement with regards to low-density lipoprotein (LDL-C) and total cholesterol (TC) there is paucity of data regarding high density lipoprotein (HDL-C), and/or triglycerides (TG).

Setting

Prospective, cross-sectional study (Dyslipidemia International Survey, DYSIS) with data provided by 748 office-based physicians throughout Germany.

Methods

Consecutive patients were eligible for participation, if they were at least 45 years old, currently treated with a statin and had had a documented lipid profile (at least 1 parameter) within the last 6 months. Besides descriptive analyses, logistic regression was performed with backward selection to assess predictors for lipid abnormalities (non-attainment of goals for TC, LDL-C, low HDL-C or elevated TG) classified according to current European Society of Cardiology guidelines.

Results

The 4,282 documented patients (98.6% Caucasian, 56.4% male; 86.6% at high cardiovascular risk) were predominantly treated with simvastatin (83.9%), pravastatin (7.7%) or atorvastatin (3.9%), usually with doses equivalent to simvastatin 20–40 mg daily. Non-statins were used in at most 12% of patients. No lipid abnormalities were found in 21.0% of patients, one abnormality in 38.5%, two in 31.9%, and all three in 8.5%. LDL-C goals were not attained in 58.1%, elevated TC was found in 66.6%, low HDL-C in 22.7%, and elevated TG in 47.3%. In the multivariate logistic regression model, non-attainment of LDL-C levels was predicted by hypertension (odds ratio, OR 1.4), current smoking (OR 1.3), sedentary lifestyle (OR 1.3), and female gender (OR 1.3). On the other hand, a reduced risk for missing LDL-C targets was noted in the presence of ischemic heart disease (OR 0.6), diabetes (0.5), higher statin doses, ezetimibe treatment, or specialist care, respectively.

Conclusion

A substantial proportion of statin-treated patients not only missed targets for LDL-C, but also did not attain the normal levels for HDL-C and/or TG. There is a large disconnect between high prevalence of HDL and/or TG disorders, with or without elevated LDL-C, and utilization of therapies targeting these lipids. Particularly in high-risk patients, additional efforts should be made to improve their lipid profile.

Systematic review on evidence of the effectiveness of cholesterol-lowering drugs

INTRODUCTION

Coronary heart disease (CHD) is the leading cause of mortality worldwide. With increasingly urbanized lifestyles in developing countries and the aging populations, the major risk factors for CHD such as obesity, diabetes mellitus, and hypercholesterolemia are likely to increase in the future. In the current report, we reviewed the evidence on the effect of cholesterol lowering using pharmacological agents.

METHODS

A PubMed/Medline systematic search was performed over the past 12 years (1998-2009 inclusive) and relevant papers written in the English language were selected. We used key phrases including, "risk factors for hypercholesterolemia," "management of hypercholesterolemia," "guidelines for management of hypercholesterolemia," and "pharmacological management of hypercholesterolemia."

RESULTS

There were a total of over 3500 reports. We selected key publications on the effect of cholesterol lowering using different pharmacological agents.

CONCLUSION

Several options exist with regards to pharmacological management of hypercholesterolemia. There is a substantial body of evidence to support the effect of a population shift towards a favorable risk profile, which has huge potential in reducing the burden of CHD globally.

Long-term follow-up of bezafibrate treatment in patients with the myopathic form of carnitine palmitoyltransferase 2 deficiency

Carnitine palmitoyltransferase 2 (CPT2) deficiency is a rare mitochondrial fatty acid oxidation (FAO) disorder characterized by myalgia, exercise intolerance, and rhabdomyolysis. We evaluate the efficacy of bezafibrate (BZ), a hypolipidemic drug, as a treatment for this form of CPT2 deficiency. A pilot trial was conducted with BZ in six patients for 6 months. There was a follow-up period of 3 years. The oxidation rates of the long-chain fatty acid derivative palmitoyl-CoA, measured in the mitochondria of the patients' muscles, were markedly lower than normal before treatment and increased significantly (+39 to +206%; P = 0.028) in all patients after BZ treatment. The evaluation of the therapeutic effects by the patients themselves (using the Short Form Health Survey (SF-36)), as well as by the physicians, indicated an improvement in the condition of the patients; there was an increase in physical activity and a decline in muscular pain. The results suggest that BZ has a therapeutic effect in the muscular form of CPT2 deficiency.

Internalization of the human nicotinic acid receptor GPR109A is regulated by G(i), GRK2, and arrestin3

Nicotinic acid (niacin) has been widely used as a favorable lipid-lowering drug for several decades, and the orphan G protein-coupled receptor GPR109A has been identified to be a receptor for niacin. Mechanistic investigations have shown that as a G(i)-coupled receptor, GPR109A inhibits adenylate cyclase activity upon niacin activation, thereby inhibiting free fatty acid liberation. However, the underlying molecular mechanisms that regulate signaling and internalization of GPR109A remain largely unknown. To further characterize GPR109A internalization, we made a construct to express GPR109A fused with enhanced green fluorescent protein (EGFP) at its carboxyl-terminal end. In stable GPR109A-EGFP-expressing HEK-293 cells, GPR109A-EGFP was mainly localized at the plasma membrane and was rapidly internalized in a dose- and time-dependent manner upon agonist stimulation. GPR109A internalization was completely blocked by hypertonic sucrose, indicating that GPR109A internalizes via the clathrin-coated pit pathway. Further investigation demonstrated that internalized GPR109A was recycled to the cell surface after the removal of agonist, and recycling of the internalized receptors was not blocked by treatment with acidotropic agents, NH(4)Cl and monensin. Pertussis toxin pretreatment not only inhibited forskolin-induced cAMP accumulation and intracellular Ca(2+) mobilization; it also significantly attenuated agonist-promoted GPR109A internalization. Moreover, RNA interference experiments showed that knockdown of GRK2 (G protein-coupled receptor kinase 2) and arrestin3 expression significantly impaired receptor internalization. Taken together, these results indicate that the agonist-induced internalization of GPR109A receptors is regulated by GRK2 and arrestin3 in a pertussis toxin-sensitive manner and that internalized receptor recycling is independent of endosomal acidification.

Discovery of a biaryl cyclohexene carboxylic acid (MK-6892): a potent and selective high affinity niacin receptor full agonist with reduced flushing profiles in animals as a preclinical candidate

Biaryl cyclohexene carboxylic acids were discovered as full and potent niacin receptor (GPR109A) agonists. Compound 1e (MK-6892) displayed excellent receptor activity, good PK across species, remarkably clean off-target profiles, good ancillary pharmacology, and superior therapeutic window over niacin regarding the FFA reduction versus vasodilation in rats and dogs.

Discovery of pyrazolyl propionyl cyclohexenamide derivatives as full agonists for the high affinity niacin receptor GPR109A

A series of pyrazolyl propionyl cyclohexenamides were discovered as full agonists for the high affinity niacin receptor GPR109A. The structure-activity relationship (SAR) studies were aimed to improve activity on GPR109A, reduce Cytochrome P450 2C8 (CYP2C8) and Cytochrome P450 2C9 (CYP2C9) inhibition, reduce serum shift and improve pharmacokinetic (PK) profiles.

Molecular imaging in atherosclerosis

Atherosclerosis is the major cause of cardiovascular disease, which still has the leading position in morbidity and mortality in the Western world. Many risk factors and pathobiological processes are acting together in the development of atherosclerosis. This leads to different remodelling stages (positive and negative) which are both associated with plaque physiology and clinical presentation. The different remodelling stages of atherosclerosis are explained with their clinical relevance. Recent advances in basic science have established that atherosclerosis is not only a lipid storage disease, but that also inflammation has a fundamental role in all stages of the disease. The molecular events leading to atherosclerosis will be extensively reviewed and described. Further on in this review different modalities and their role in the different stages of atherosclerosis will be discussed. Non-nuclear invasive imaging techniques (intravascular ultrasound, intravascular MRI, intracoronary angioscopy and intravascular optical coherence tomography) and non-nuclear non-invasive imaging techniques (ultrasound with Doppler flow, electron-bean computed tomography, coronary computed tomography angiography, MRI and coronary artery MR angiography) will be reviewed. After that we focus on nuclear imaging techniques for detecting atherosclerotic plaques, divided into three groups: atherosclerotic lesion components, inflammation and thrombosis. This emerging area of nuclear imaging techniques can provide measures of biological activity of atherosclerotic plaques, thereby improving the prediction of clinical events. As we will see in the future perspectives, at present, there is no special tracer that can be called the diagnostic tool to diagnose prospective stroke or infarction in patients. Nevertheless, we expect such a tracer to be developed in the next few years and maybe, theoretically, it could even be used for targeted therapy (in the form of a beta-emitter) to combat cardiovascular disease.

Comparison of sequential rosuvastatin doses in hypercholesterolaemia: a meta-analysis of randomised controlled trials

BACKGROUND

Rosuvastatin is an effective treatment for patients with hypercholesterolaemia. However, the incremental benefit and risk of increasing through the licensed dose range have not been comprehensively assessed across all available clinical trials.

RESEARCH DESIGN AND METHODS

The literature databases CENTRAL, EMBASE, and MEDLINE were searched in April 2008 for trials with comparisons of sequential licensed rosuvastatin dosages: 5 vs. 10 mg/day, 10 vs. 20 mg/day, and 20 vs. 40 mg/day. Clinical trial registries were also searched. For benefit outcomes, weighted mean differences were derived using the inverse variance method. For risk outcomes, the Mantel-Haenszel method was used to calculate a summary relative risk.

RESULTS

The meta-analysis included 26 trials. The results demonstrated significantly favourable changes in low-density lipoprotein cholesterol level with increasing dosage (by 6.25, 5.84, and 5.03 percentage points for 10 vs. 5 mg/day, 20 vs. 10 mg/day, and 40 vs. 20 mg/day, respectively), and also in the ratios of total cholesterol to high-density lipoprotein cholesterol (HDL-C) and apolipoprotein B to apolipoprotein A-I (all p < 0.00001). In addition, a significantly favourable change in HDL-C level was found with 20 mg/day over 10 mg/day (p = 0.02). Among the primary tolerability comparisons, no significant differences in risk were seen for muscular, hepatic, or renal adverse events, with only one exception: the risk of proteinuria by urine dipstick testing was significantly higher with rosuvastatin 40 mg/day than 20 mg/day (p = 0.01). The efficacy outcomes assessed in this meta-analysis are limited to surrogate markers of morbidity and mortality.

CONCLUSIONS

This meta-analysis provides evidence for improved efficacy in treating patients with hypercholesterolaemia with each sequential titration of rosuvastatin and a generally consistent tolerability profile across the dose range.

Niacin and fibrates in atherogenic dyslipidemia: pharmacotherapy to reduce cardiovascular risk

Although statin therapy represents a cornerstone of cardiovascular disease (CVD) prevention, a major residual CVD risk (60-70% of total relative risk) remains, attributable to both modifiable and non-modifiable risk factors. Among the former, low levels of HDL-C together with elevated triglyceride (TG)-rich lipoproteins and their remnants represent major therapeutic targets. The current pandemic of obesity, metabolic syndrome, and type 2 diabetes is intimately associated with an atherogenic dyslipidemic phenotype featuring low HDL-C combined with elevated TG-rich lipoproteins and small dense LDL. In this context, there is renewed interest in pharmacotherapeutic strategies involving niacin and fibrates in monotherapy and in association with statins. This comprehensive, critical review of available data in dyslipidemic subjects indicates that niacin is more efficacious in raising HDL-C than fibrates, whereas niacin and fibrates reduce TG-rich lipoproteins and LDL comparably. Niacin is distinguished by its unique capacity to effectively lower Lp(a) levels. Several studies have demonstrated anti-atherosclerotic action for both niacin and fibrates. In contrast with statin therapy, the clinical benefit of fibrates appears limited to reduction of nonfatal myocardial infarction, whereas niacin (frequently associated with statins and/or other agents) exerts benefit across a wider range of cardiovascular endpoints in studies involving limited patient numbers. Clearly the future treatment of atherogenic dyslipidemias involving the lipid triad, as exemplified by the occurrence of the mixed dyslipidemic phenotype in metabolic syndrome, type 2 diabetes, renal, and auto-immune diseases, requires integrated pharmacotherapy targeted not only to proatherogenic particles, notably VLDL, IDL, LDL, and Lp(a), but also to atheroprotective HDL.

Men presenting for radical prostatectomy on preoperative statin therapy have reduced serum prostate specific antigen

PURPOSE

Studies have suggested that statin (3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors) medication use may decrease prostate specific antigen in healthy men. We determined the effect of preoperative statin use on total preoperative prostate specific antigen and the risk of biochemical recurrence in patients with prostate cancer presenting for radical prostatectomy.

MATERIALS AND METHODS

A retrospective review of 3,828 patients undergoing radical prostatectomy from January 2001 to July 2008 at our institution identified 1,031 on statin medications. We compared these 1,031 patients to the remaining 2,797 not on statins preoperatively. We evaluated differences in prostate specific antigen overall, and when patients were stratified by age specific groups, body mass index and Gleason grades on final pathology. We also investigated differences in biochemical recurrence rates.

RESULTS

Overall median serum prostate specific antigen was lower in patients on preoperative statins (5.0 vs 5.2 ng/ml, p = 0.002). Median prostate specific antigen was lower in men on statins with Gleason grades 7 or 8/9 disease (p <0.05). Using a multivariate logistic regression model statin therapy was associated with a 4.7% decrease in prostate specific antigen (p <0.001). Statin therapy was not associated with an overall decreased risk of biochemical recurrence (p = 0.73) at a mean followup of 26 months.

CONCLUSIONS

In this cohort of men presenting for radical prostatectomy serum prostate specific antigen is significantly lower in patients with prostate cancer on preoperative statins compared to those not taking these medications. Prospective studies are required to evaluate if this decrease in prostate specific antigen leads to later detection of prostate cancer or variations in oncological outcomes.

Population-based health-economic evaluation of the secondary prevention of coronary heart disease in Finland

OBJECTIVE

To evaluate the cost-effectiveness of generic atorvastatin 20 mg (A20), branded rosuvastatin 10 mg (R10), generic simvastatin 40 mg (S40) and the combination of generic S40 + branded ezetimibe 10 mg (S40 + EZ10) for the secondary prevention of coronary heart disease (CHD) in Finnish patients not meeting the target goal of low-density lipoprotein cholesterol (LDL-C) with S40.

RESEARCH DESIGN AND METHODS

A probabilistic Markov model was employed to evaluate the costs and health outcomes of the different therapies based on the cardiovascular events avoided. The model included Framingham risk equations, Finnish population characteristics, event rates, quality of life estimates, resource use and unit costs. The LDL-C lowering efficacies were gathered from a systematic literature review, based on a search of Medline carried out in June 2008 (no time limit).

MAIN OUTCOME MEASURES

Incremental cost per quality-adjusted life year (QALY) gained and incremental cost per life year gained (LYG).

RESULTS

The efficacy (LDL-C decrease) gained from switching S40 to S40 + EZ10 was consistent in the literature review, whereas the LDL-C decrease gained from switching S40 to A20/R10 was uncertain. The incremental cost per QALY gained from switching generic S40 was lowest for S40 + EZ10 (22,841 euros [24,017 euros] and 26,595 euros [46,686 euros] for diabetic and non-diabetic men [women], respectively). The respective incremental cost per QALY gained for S40 + EZ10 vs. A20 were 19,738 euros (21,405 euros) and 23,596 euros (40,087 euros). A20 dominated R10. Based on the cost-effectiveness acceptability frontier with a willingness-to-pay value of 30,000 euros per QALY gained, the probability of cost-effectiveness for switching generic S40 to S40 + EZ10 was 100% for men and diabetic women. Sensitivity analyses showed that results were robust.

CONCLUSIONS

In the Finnish secondary prevention population that is not at goal on S40, switching generic S40 to S40 + EZ10 is more cost-effective than switching S40 to generic A20 or R10.

Cardiovascular and economic outcomes after initiation of lipid-lowering therapy with atorvastatin vs simvastatin in an employed population

OBJECTIVE

To compare the risk of cardiovascular-related hospitalization, statin adherence, and direct (medical and drug) and indirect (disability and medically related absenteeism) costs in US employees in whom atorvastatin or simvastatin was newly prescribed.

PATIENTS AND METHODS

Active employees aged 18 to 64 years with a new atorvastatin or simvastatin prescription were identified from a deidentified claims database for 23 privately insured US companies from January 1, 1999, through December 31, 2006. Employees given atorvastatin were matched to those given simvastatin according to propensity scores based on patient characteristics, index statin dose, preindex cardiovascular events, and wage. Outcomes were compared between matched cohorts during the 2-year postindex period, including the risk of cardiovascular-related hospitalization, adherence to the index statin, use of other lipid-lowering drugs, direct medical costs for third-party payers, and indirect costs to employers. Indirect costs were computed as follows: Disability Payments + Daily Wage x Days of Medically Related Absenteeism. Atorvastatin and simvastatin drug costs were imputed using recent pricing to account for the availability of lower-cost generic simvastatin after the study period.

RESULTS

Among 13,584 matched pairs, treatment with atorvastatin vs simvastatin was associated with a reduced risk of cardiovascular-related hospitalization, higher adherence, and less use of other lipid-lowering drugs. The increase in statin costs associated with atorvastatin vs simvastatin therapy was almost completely offset by reductions in medical service and indirect costs.

CONCLUSION

In this study, treatment with atorvastatin compared with simvastatin was associated with a reduced risk of cardiovascular events, reduced indirect costs, and a minimal difference in total costs to employers.

Review of extended-release niacin/laropiprant fixed combination in the treatment of mixed dyslipidemia and primary hypercholesterolemia

Although statins reduce cardiovascular morbidity and mortality further risk reduction is needed. In this respect low HDL-cholesterol concentrations and/or elevated triglyceride concentrations may be potential treatment targets. Niacin (nicotinic acid) is an effective drug which increases the plasma concentration of high-density lipoprotein (HDL)-cholesterol and decreases the concentration of low-density lipoprotein (LDL)-cholesterol, triglycerides and lipoprotein(a). Clinical studies indicate that niacin can significantly reduce the risk for cardiovascular events. However, niacin is not very commonly used because of significant side effects (especially flushing). Laropiprant is a potent selective antagonist of PGD2-receptor subtype-1 and can thus reduce niacin-induced flushing. Although the addition of laropiprant will reduce the frequency of flushing, it will not completely eliminate this side effect. Laropiprant does not change the effect of niacin on lipids or other side effects of niacin (ie, gastro-intestinal problems, glucose elevation). The combination of niacin with laropiprant may therefore enable use of niacin at higher doses and therefore exploit the full potential of the drug. Endpoint studies that will be published over the next few years will show whether this treatment modality also translates into clinical effect in patients treated with statins. Until publication of these studies niacin/laropiprant should be used only in high-risk patients not achieving lipid goals on statins.

Major lipids, apolipoproteins, and risk of vascular disease

CONTEXT

Associations of major lipids and apolipoproteins with the risk of vascular disease have not been reliably quantified.

OBJECTIVE

To assess major lipids and apolipoproteins in vascular risk.

DESIGN, SETTING, AND PARTICIPANTS

Individual records were supplied on 302,430 people without initial vascular disease from 68 long-term prospective studies, mostly in Europe and North America. During 2.79 million person-years of follow-up, there were 8857 nonfatal myocardial infarctions, 3928 coronary heart disease [CHD] deaths, 2534 ischemic strokes, 513 hemorrhagic strokes, and 2536 unclassified strokes.

MAIN OUTCOME MEASURES

Hazard ratios (HRs), adjusted for several conventional factors, were calculated for 1-SD higher values: 0.52 log(e) triglyceride, 15 mg/dL high-density lipoprotein cholesterol (HDL-C), 43 mg/dL non-HDL-C, 29 mg/dL apolipoprotein AI, 29 mg/dL apolipoprotein B, and 33 mg/dL directly measured low-density lipoprotein cholesterol (LDL-C). Within-study regression analyses were adjusted for within-person variation and combined using meta-analysis.

RESULTS

The rates of CHD per 1000 person-years in the bottom and top thirds of baseline lipid distributions, respectively, were 2.6 and 6.2 with triglyceride, 6.4 and 2.4 with HDL-C, and 2.3 and 6.7 with non-HDL-C. Adjusted HRs for CHD were 0.99 (95% CI, 0.94-1.05) with triglyceride, 0.78 (95% CI, 0.74-0.82) with HDL-C, and 1.50 (95% CI, 1.39-1.61) with non-HDL-C. Hazard ratios were at least as strong in participants who did not fast as in those who did. The HR for CHD was 0.35 (95% CI, 0.30-0.42) with a combination of 80 mg/dL lower non-HDL-C and 15 mg/dL higher HDL-C. For the subset with apolipoproteins or directly measured LDL-C, HRs were 1.50 (95% CI, 1.38-1.62) with the ratio non-HDL-C/HDL-C, 1.49 (95% CI, 1.39-1.60) with the ratio apo B/apo AI, 1.42 (95% CI, 1.06-1.91) with non-HDL-C, and 1.38 (95% CI, 1.09-1.73) with directly measured LDL-C. Hazard ratios for ischemic stroke were 1.02 (95% CI, 0.94-1.11) with triglyceride, 0.93 (95% CI, 0.84-1.02) with HDL-C, and 1.12 (95% CI, 1.04-1.20) with non-HDL-C.

CONCLUSION

Lipid assessment in vascular disease can be simplified by measurement of either total and HDL cholesterol levels or apolipoproteins without the need to fast and without regard to triglyceride.

Acyl hydroxypyrazoles as novel agonists for high-affinity nicotinic acid receptor GPR109A: WO2008051403

BACKGROUND

Acyl hydroxypyrazoles were discovered and claimed by Merck as novel agonists for the high-affinity nicotinic acid receptor, G-protein coupled receptor 109A (GPR109A). The fused bicyclic core contains a hydroxypyrazole that mimics the anthranilide moiety described in their earlier patents and patent publications.

OBJECTIVE

This article evaluates new GPR109A receptor agonists disclosed by Merck in the recent patent WO2008051403.

CONCLUSION

The aim of this invention was to provide potential therapy to reduce free fatty acids (FFA), low-density lipoprotein cholesterol (LDL-C), total cholesterol, and serum triglycerides (TG), and to raise high-density lipoprotein cholesterol (HDL-C). Thus, these agonists could - potentially - be used to treat dyslipidemia, atherosclerosis, and metabolic syndromes such as diabetes.

Mylip makes an Idol turn into regulation of LDL receptor

High blood low-density-lipoprotein (LDL) cholesterol is a serious health problem among an increased number of patients in the Western world. Statins and other cholesterol lowering drugs have proven to be beneficial as therapy but are not optimal and show adverse effects in some patients. The LDL receptor is a crucial determinant of cholesterol metabolism in the body and amenable for drug interventions. Novel insights into the physiology of this receptor come from studies on the ubiquitination and degradation of LDL receptor by the ubiquitin ligase Mylip/Idol that is induced in cells by the nuclear receptor, LXR. This may open up new possibilities in the future to influence LDL receptor levels and cholesterol metabolism pharmacologically in various diseases.

Single-dose pharmacokinetics and pharmacodynamics of anacetrapib, a potent cholesteryl ester transfer protein (CETP) inhibitor, in healthy subjects

AIMS

Anacetrapib is an orally active and potent inhibitor of CETP in development for the treatment of dyslipidaemia. These studies endeavoured to establish the safety, tolerability, pharmacokinetics and pharmacodynamics of rising single doses of anacetrapib, administered in fasted or fed conditions, and to preliminarily assess the effect of food, age, gender and obesity on the single-dose pharmacokinetics and pharmacodynamics of anacetrapib.

METHODS

Safety, tolerability, anacetrapib concentrations and CETP activity were evaluated.

RESULTS

Anacetrapib was rapidly absorbed, with peak concentrations occurring at approximately 4 h post-dose and an apparent terminal half-life ranging from approximately 9 to 62 h in the fasted state and from approximately 42 to approximately 83 h in the fed state. Plasma AUC and C(max) appeared to increase in a less than approximately dose-dependent manner in the fasted state, with an apparent plateau in absorption at higher doses. Single doses of anacetrapib markedly and dose-dependently inhibited serum CETP activity with peak effects of approximately 90% inhibition at t(max) and approximately 58% inhibition at 24 h post-dose. An E(max) model best described the plasma anacetrapib concentration vs CETP activity relationship with an EC(50) of approximately 22 nm. Food increased exposure to anacetrapib; up to approximately two-three-fold with a low-fat meal and by up to approximately six-eight fold with a high-fat meal. Anacetrapib pharmacokinetics and pharmacodynamics were similar in elderly vs young adults, women vs men, and obese vs non-obese young adults. Anacetrapib was well tolerated and was not associated with any meaningful increase in blood pressure.

CONCLUSIONS

Whereas food increased exposure to anacetrapib significantly, age, gender and obese status did not meaningfully influence anacetrapib pharmacokinetics and pharmacodynamics.

Novel patent publications on high-affinity nicotinic acid receptor agonists

BACKGROUND

Nicotinic acid (NA) has been used as a drug to treat dyslipidemia for > 50 years. In outcome clinical trials, NA displayed remarkable efficacy in patients with cardiovascular diseases by modifying lipid profiles that results in reduced morbidity and mortality. On the other hand, NA induces vasodilation (flushing) that undermines treatment compliance. In addition, high-dose treatment is required presumably owing to the poor pharmacokinetic properties of NA. The identification of the high-affinity NA receptor, namely G-protein coupled receptor 109A (GPR109A), led to further understanding of the pharmacological effects of NA and discovery of compounds that are potentially superior in efficacy yet devoid of NA's adverse effects.

OBJECTIVE/METHOD

This review focuses on the endeavors of several pharmaceutical companies to discover and develop GPR109A agonists. Representative compounds of each series in patent literature since 2005 are highlighted.

CONCLUSION

Highly potent GPR109A agonists with minimal flushing effects and robust free fatty acid reduction have been identified. Despite the failure of the partial agonist MK-0354 to achieve efficacy in a Phase II clinical trial, at least three other GPR109A agonists have been evaluated in clinical trials. The upcoming clinical data would be critical to validate the therapeutic utility of this receptor.

Anti-inflammatory effects of nicotinic acid in adipocytes demonstrated by suppression of fractalkine, RANTES, and MCP-1 and upregulation of adiponectin

OBJECTIVE

A major site of action for the atheroprotective drug nicotinic acid (NA) is adipose tissue, via the G-protein-coupled receptor, GPR109A. Since, adipose tissue is an active secretory organ that contributes both positively and negatively to systemic inflammatory processes associated with cardiovascular disease, we hypothesized that NA would act directly upon adipocytes to alter the expression of pro-inflammatory chemokines, and the anti-inflammatory adipokine adiponectin.

METHODS AND RESULTS

TNF-alpha treatment (1.0ng/mL) of 3T3-L1 adipocytes resulted in an increase in gene expression of fractalkine (9+/-3.3-fold, P<0.01); monocyte chemoattractant protein-1 (MCP-1) (24+/-1.2-fold, P<0.001), 'regulated upon activation, normal T cell expressed and secreted' (RANTES) (500+/-55-fold, P<0.001) and inducible nitric oxide synthase (iNOS) (200+/-70-fold, P<0.05). The addition of NA (10(-4)M) to TNF-alpha-treated adipocytes attenuated expression of fractalkine (50+/-12%, P<0.01); MCP-1 (50+/-6%, P<0.01), RANTES (70+/-3%, P<0.01) and iNOS (60+/-16%). This pattern was mirrored in protein released from the adipocytes into the surrounding media. The effect on gene expression was neutralised by pre-treatment with pertussis toxin. NA attenuated macrophage chemotaxis (by 27+/-3.5%, P<0.001) towards adipocyte conditioned media. By contrast, NA, (10(-6)-10(-3)M) increased, in a dose-dependent manner, mRNA of the atheroprotective hormone adiponectin (3-5-fold n=6, P<0.01).

CONCLUSIONS

NA suppresses pro-atherogenic chemokines and upregulates the atheroprotective adiponectin through a G-protein-coupled pathway. Since adipose tissue has the potential to contribute to both systemic and local (perivascular) inflammation associated with atherosclerosis our results suggest a new "pleiotropic" role for NA.

What do the statin trials tell us?

The results of five large-scale, randomized, placebo-controlled trials, involving nearly 31,000 subjects, attest to the benefits of statins in the prevention of coronary events. Several key observations can be made on the basis of the evidence from these investigations. Of primary importance is the fact that statins reduce coronary event rates in patients with or without coronary heart disease. The percentage reduction in risk increases with each successive year of statin therapy. Moreover, the risk reduction is proportional to the reduction in low-density lipoprotein cholesterol. Subgroup analyses have demonstrated that the efficacy of statins extends to specific subgroups of patients, including women, people with diabetes, and older individuals. These agents also reduce the risk of stroke and transient ischemic attacks in patients with coronary disease. Both the randomized trials and widespread clinical experience have confirmed that statins are safe and do not increase the risk of cancer or mortality. Several markers of atherosclerotic risk are ameliorated by statins, although the clinical significance of this observation remains under investigation. The broad range of the therapeutic effects of statins yields safe, effective management of hypercholesterolemia in current practice while also providing a foundation for additional therapeutic refinements in the future.

Low incidence of cardiac events in statin-administered patients in CAG study

AIM

The effect of statins in preventing cardiac events in Japanese coronary artery disease (CAD) patients was studied in a retrospective investigation of 148 patients diagnosed with CAD by coronary angiography (CAG).

METHODS

Sixty-five patients received statins within 2 weeks after CAG, and 83 patients did not receive statins after CAG.

RESULTS

In the statin group, total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were reduced significantly with statin administration (p<0.01). In the non-statin group, baseline levels of TC, LDL-C and high-density lipoprotein cholesterol were not changed significantly at the end of the follow-up period. As for the effect of statin in preventing cardiac events, the incidence of cardiac events was significantly lower (p<0.0003) in the statin group (n=5: 8%) than in the non-statin group (n=28: 34%). In subanalysis of 37 patients whose TC at the time of initial CAG was less than 200 mg/dL, none of the statin group (n=17) suffered a cardiac event. This was significantly lower than the incidence of cardiac events in the non-statin group (n=5: 25%; p<0.05).

CONCLUSION

The present study demonstrated that lowering LDL-C of Japanese CAD patients by statin administration is effective to prevent cardiac events, particularly, a second percutaneous coronary intervention (PCI) for restenosis of a coronary artery following the initial PCI whether or not these patients had hypercholesterolemia.

Significance of peroxisome proliferator-activated receptors in the cardiovascular system in health and disease

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear transcription factors that belong to the nuclear receptor superfamily. Three isoforms of PPAR have been identified, alpha, delta and gamma, which play distinct roles in the regulation of key metabolic processes, such as glucose and lipid redistribution. PPARalpha is expressed predominantly in the liver, kidney and heart, and is primarily involved in fatty acid oxidation. PPARgamma is mainly associated with adipose tissue, where it controls adipocyte differentiation and insulin sensitivity. PPARdelta is abundantly and ubiquitously expressed, but as yet its function has not been clearly defined. Activators of PPARalpha (fibrates) and gamma (thiazolidinediones) have been used clinically for a number of years in the treatment of hyperlipidaemia and to improve insulin sensitivity in diabetes. More recently, PPAR activation has been found to confer additional benefits on endothelial function, inflammation and thrombosis, suggesting that PPAR agonists may be good candidates for the treatment of cardiovascular disease. In this regard, it has been demonstrated that PPAR activators are capable of reducing blood pressure and attenuating the development of atherosclerosis and cardiac hypertrophy. This review will provide a detailed discussion of the current understanding of basic PPAR physiology, with particular reference to the cardiovascular system. It will also examine the evidence supporting the involvement of the different PPAR isoforms in cardiovascular disease and discuss the current and potential future clinical applications of PPAR activators.

Discovery of novel tricyclic full agonists for the G-protein-coupled niacin receptor 109A with minimized flushing in rats

Tricyclic analogues were rationally designed as the high affinity niacin receptor G-protein-coupled receptor 109A (GPR109A) agonists by overlapping three lead structures. Various tricyclic anthranilide and cycloalkene carboxylic acid full agonists were discovered with excellent in vitro activity. Compound 2g displayed a good therapeutic index regarding free fatty acids (FFA) reduction and vasodilation effects in rats, with very weak cytochrome P450 2C8 (CYP2C8) and cytochrome P450 2C9 (CYP2C9) inhibition, and a good mouse pharmacokinetics (PK) profile.

Analysis of skeletal status by quantitative ultrasonometry in a cohort of postmenopausal women with high blood cholesterol without documented osteoporosis

Osteoporosis and atherosclerosis are leading causes of mortality and morbidity in the Western world. A link between osteoporosis and atherosclerosis was proposed by epidemiologic and laboratory data. In the present study, we investigated skeletal status in postmenopausal women with hypercholesterolemia using quantitative ultrasonometry (QUS). Six hundred healthy postmenopausal subjects were enrolled within a 2-mo period by primary care physicians. Information on lifestyle and calcium intake was collected for each enrolled subject. Subjects (n = 256) were divided into two groups according to lipid profile: normal (n = 180) with serum cholesterol <200 mg/dL and hypercholesterolemic (n = 76) with serum cholesterol >or=200 mg/dL. Hypercholesterolemic subjects were further stratified into two groups, one receiving dietary treatment (n = 34) and the other receiving statin treatment (n = 42). We found a statistically significant reduction in amplitude dependent speed of sound (AD-SoS) in hypercholesterolemic subjects compared with subjects with normal cholesterol (p = 0.006). Calcium intake behaved similarly to AD-SoS (p = 0.0001). No statistical significant difference in AD-SoS were observed between the group on diet treatment versus the group on statin (p = 0.52). Calcium intake was lower in patients on statins treatment compared with subjects on diet treatment only (p < 0.0001). Our data suggest that hypercholesterolemia per se is a risk factor for impaired skeletal status. Our data also call attention to the risk of a poor calcium intake in patient receiving diet to lower plasma cholesterol. Moreover, our data suggest that statins per se may exert a protective effect on bone independently from calcium intake.

Synthesis and biological evaluation of a series of liver-selective phosphonic acid thyroid hormone receptor agonists and their prodrugs

Phosphonic acid (PA) thyroid hormone receptor (TR) agonists were synthesized to exploit the poor distribution of PA-based drugs to extrahepatic tissues and thereby to improve the therapeutic index. Nine PAs showed excellent TR binding affinities (TRbeta(1), K(i) < 10 nM), and most of them demonstrated significant cholesterol lowering effects in a cholesterol-fed rat (CFR) model. Unlike the corresponding carboxylic acid analogue and T(3), PA 22c demonstrated liver-selective effects by inducing maximal mitochondrial glycerol-3-phosphate dehydrogenase activity in rat liver while having no effect in the heart. Because of the low oral bioavailability of PA 22c, a series of prodrugs was synthesized and screened for oral efficacy in the CFR assay. The liver-activated cyclic 1-(3-chlorophenyl)-1,3-propanyl prodrug (MB07811) showed potent lipid lowering activity in the CFR (ED(50) 0.4 mg/kg, po) and good oral bioavailability (40%, rat) and was selected for development for the treatment of hypercholesterolemia.

Lowering low-density lipoprotein cholesterol: statins, ezetimibe, bile acid sequestrants, and combinations: comparative efficacy and safety

Statins, ezetimibe, and bile acid-binding resins can be used individually or in combination for lowering low-density lipoprotein cholesterol (LDL-C) levels. Statins are the most potent drugs for lowering LDL-C and are well tolerated in most patients. The addition of a bile acid sequestrant or ezetimibe to a statin produces additional LDL-C reduction allowing many patients to reach LDL-C targets. This article discusses the efficacy and safety of available statins, bile acid sequestrants, and ezetimibe in the treatment of hyperlipidemia.

Low-dose combination therapy with colesevelam hydrochloride and lovastatin effectively decreases low-density lipoprotein cholesterol in patients with primary hypercholesterolemia

BACKGROUND

Colesevelam hydrochloride is a novel, lipid-lowering agent that binds bile acids with high affinity. A multicenter, randomized, double-blind, placebo-controlled, parallel-design study was conducted to assess the efficacy and tolerability of combination low-dose colesevelam and lovastatin treatment in patients with primary hypercholesterolemia.

HYPOTHESIS

Combination therapy with low doses of colesevelam and lovastatin decreases low density (LDL) cholesterol with minimal adverse events.

METHODS

Following a 4- to 6-week dietary lead in, 135 patients were randomized into five groups for a 4-week treatment period: placebo, colesevelam 2.3 g at dinner, lovastatin 10 mg at dinner, the combination of colesevelam and lovastatin given at dinner (dosed together), and combination treatment with colesevelam given at dinner and lovastatin administered at bedtime (dosed apart).

RESULTS

Combination colesevelam and lovastatin treatment decreased LDL cholesterol by 34% (60 mg/dl, p < 0.0001) and 32% (53 mg/dl, p < 0.0001) when colesevelam and lovastatin were dosed together or dosed apart, respectively. Both combination therapies were superior to either agent alone (p < 0.05). Decreases in LDL cholesterol exceeded the combined decreases observed for colesevelam alone (13 mg/dl, 7%) and lovastatin alone (39 mg/dl, 22%). Both combination treatments reduced total cholesterol by 21% (p < 0.0001) and apolipoprotein B by 24% (p < 0.0001). Neither combination treatment significantly altered high-density lipoprotein cholesterol or triglycerides. Adverse side effects were not significantly different among randomized groups.

CONCLUSIONS

Combination colesevelam and lovastatin was efficacious and well tolerated, resulting in additive decreases in LDL cholesterol levels whether or not both agents were administered simultaneously.

The SLIM Study: Slo-Niacin® and Atorvastatin Treatment of Lipoproteins and Inflammatory Markers in Combined Hyperlipidemia

BACKGROUND: The combination of niacin and statin has proven value in hyperlipidemia management and heart disease prevention. However, the efficacy of the non-prescription time-release niacin, Slo-Niacin®, is little studied alone and not at all with atorvastatin. We gave Slo-Niacin® and atorvastatin, singly and together to determine efficacy on the combined abnormalities of triglyceride, LDL and HDL. METHODS: 42 men and women with LDL-C>130mg/dL HDL-C <45 (men or 55mg/dL (women) were randomized to 3 months of atorvastatin 10 mg/day or incremental doses of Slo-Niacin® to 1500 mg/day. The alternate drug was added in the next 3-month segment. Lipid profiles and transaminases were measured monthly and other measures at baseline and the end of each treatment sequence. RESULTS: Mean entry lipids (mg/dL) were: TG 187, LDL-C 171, and HDL-C 39. Mean BMI was 32.6 Kg/m(2). Monotherapy with Slo-Niacin® decreased median triglyceride 15%, mean LDL-C 12% and non-HDL-C 15% and increased HDL-C 8%. Atorvastatin decreased median triglyceride 26%, and mean LDL-C 36%, non-HDL-C 36% and increased HDL-C 6%. Combined therapy decreased median triglyceride 33% and mean LDL-C and non-HDL-C each 43%. HDL-C increased 10% (all p<0.001). Median remnant-like lipoprotein-C decreased 55%, mean apo-B 40%, median hsCRP 23% (all p<0.05), TNFa 12% and no change in IL-6. Mean LDL buoyancy increased 15%, apo-A-I 5% and median HDL(2)-C 20% (all p<0.05). ALT declined with Slo-Niacin® treatment alone compared to atorvastatin and also decreased when Slo-Niacin® was added to atorvastatin. Six subjects dropped out, 3 for niacin related symptoms. CONCLUSIONS: Slo-Niacin® 1.5g/day with atorvastatin 10 mg/day improved lipoprotein lipids, apoproteins and inflammation markers without hepatotoxicity. Slo-Niacin® deserves further study as a cost-effective treatment of hyperlipidemia.

Rationale and design of the carotid plaque in human for all evaluations with aggressive rosuvastatin therapy (CHALLENGER trial): evaluation by magnetic resonance imaging

BACKGROUND

Intensive lipid-lowering therapy with statins reduces levels of low-density lipoprotein (LDL)-cholesterol (C) and improves plaque volume and composition in patients with cardiovascular disease. Furthermore, rosuvastatin ameliorated carotid stenosis in the ASTEROID study, and altered the composition of plaques in a predominantly Caucasian study population in the ORION study. However, it is not known whether statin therapy achieves similar quantitative improvement in carotid artery plaque in other ethnic groups.

METHODS AND RESULTS

Fifty patients with hypercholesterolemia (LDL-C >or=120 mg/dl) and a maximum carotid intima-media thickness >or=1.8 mm will be enrolled and treated with rosuvastatin at a dose of 5 mg/day for 96 weeks. The primary endpoints will be the percent change of carotid plaque volume and the change in plaque composition after 96 weeks of treatment, as evaluated by magnetic resonance imaging.

CONCLUSIONS

The CHALLENGER study will provide a noninvasive assessment of the changes in carotid plaque volume and composition achieved by reduction of LDL levels in Japanese patients with carotid stenosis on long-term rosuvastatin therapy.

The influence of simvastatin, atorvastatin and high-cholesterol diet on acetylcholinesterase activity, amyloid beta and cholesterol synthesis in rat brain

OBJECTIVE

There is evidence to suppose that cholesterol-lowering medicine might confer protection against dementia, probably via modulation of cholesterol synthesis in the brain. The aim of the present study was to investigate the potential influence of statins and cholesterol diet on selected parameters relevant to Alzheimer's disease pathophysiology.

METHODS

For 15 days, rats were orally administered simvastatin (10 or 20mg/kg b.wt.), atorvastatin (10 or 20mg/kg b.wt.), or aqua (control group); and one group was fed high-cholesterol (2%) diet. At the end of experiments brain (and plasma) cholesterol, lathosterol, hydroxymethylglutaryl-coenzyme A reductase protein, acetylcholinesterase activity, amyloid beta (40 and 42) and cholesterol synthesis rate (using the incorporation of deuterium from deuterated water) were determined and statistically compared to those of aqua.

RESULTS

Both statins were able to lower cholesterol in the plasma, but none elicited an effect on total brain cholesterol. Significant reductions of brain lathosterol and cholesterol synthesis rate were observed after simvastatin and atorvastatin treatment. Acetylcholinesterase activity, amyloid beta and hydroxymethylglutaryl-coenzyme A reductase levels remained unaffected by the two drugs.

CONCLUSIONS

This study brings additional evidence of a role for statins in cholesterol synthesis in the brain. Our data question the relationship between amyloid beta, acetylcholinesterase activity and cholesterol synthesis in the rat brain as well as the assumption about no exchange between peripheral and brain cholesterol pools.

Review article: The use of potentially hepatotoxic drugs in patients with liver disease

BACKGROUND

Misconceptions surround the use of hepatotoxic drugs in chronic liver disease. While many prescription and over-the-counter (OTC) agents can be used safely, this often runs counter to labelled warnings/contraindications, especially for the statins and other commonly used agents.

AIM

To evaluate published data on the use of hepatotoxic drugs in chronic liver disease including pharmacokinetic changes in cirrhosis and drug interactions, where available, to formulate recommendations on their use.

METHODS

Using a combination of PubMed searches, review texts, the Physicians' Desk Reference and expert opinion, drugs considered at higher risk of hepatotoxicity in chronic liver disease were evaluated.

RESULTS

Most drugs and OTC products including herbals have not been formally studied in chronic liver disease, but available data suggest that several of the most commonly used agents, especially the statins, can be used safely. While there is an increased risk of drug-induced liver injury for drugs used in the treatment of tuberculosis and HIV patients with hepatitis B or C, recommendations for their safe use are emerging.

CONCLUSIONS

Although many clinicians remain hesitant to use hepatotoxic drugs in chronic liver disease, the database supporting this view is limited to just a few agents. Most medications can be used safely in patients with chronic liver disease with appropriate monitoring.

Improvement of dyslipidemia, insulin sensitivity, and energy balance by a peroxisome proliferator-activated receptor alpha agonist

Peroxisome proliferator-activated receptor alpha (PPARalpha) is a member of the nuclear receptor family of ligand-activated transcription factors. It plays an important role in the regulation of genes involved in lipid metabolism and transport. Compound A is a potent and orally active PPARalpha agonist that activated both human and rat PPARalpha receptors. The compound induced the expression of genes involved in fatty acid metabolism in a rodent hepatoma cell line and in the liver of db/db mouse. The ability of compound A to stimulate fatty acid beta-oxidation was demonstrated in human hepatocytes and human skeletal muscle cells, which confirmed a functional activation of PPARalpha-mediated activities. Compound A was shown to be a more potent and efficacious antidyslipidemic agent in atherogenic rat and db/db mouse models as compared with fenofibrate. The increase in high-density lipoprotein cholesterol levels by compound A was at least partially due to an increase in serum apolipoprotein A-I protein concentrations in human PPARalpha transgenic mouse. The triglyceride-lowering effect was further confirmed in a higher species, obese dog models. In addition, compound A dose-dependently ameliorated hyperglycemia and hyperinsulinemia, and improved glucose tolerance in db/db mice. In a diet-induced obesity mouse model, compound A decreased body weight mainly by increasing energy expenditure and reducing fat deposition. In conclusion, the novel and potent PPARalpha agonist improves lipid profile, insulin sensitivity, and energy balance in animal models.

Cholesterol-metabolizing cytochromes P450: implications for cholesterol lowering

Cardiovascular disease (CVD) continues to be a leading cause of death worldwide. Elevated serum cholesterol is one of the classical risk factors for CVD, which also include age, hypertension, smoking, diabetes mellitus, obesity and family history. Several therapeutic drug classes have been developed to treat hypercholesterolemia; yet, an important percentage of patients do not reach their treatment goals. Therefore, new cholesterol-lowering medications that have sites of action different from that of drugs available at present need to be developed. This review summarizes new information about cytochrome P450 enzymes 7A1, 27A1 and 46A1. These enzymes play key roles in cholesterol elimination and have the potential to serve as targets for cholesterol-lowering.

Long-term (48-week) safety of ezetimibe 10 mg/day coadministered with simvastatin compared to simvastatin alone in patients with primary hypercholesterolemia

OBJECTIVE

This study evaluated the long-term safety and tolerability of ezetimibe/simvastatin coadministration therapy compared to simvastatin monotherapy in patients with primary hypercholesterolemia.

RESEARCH DESIGN AND METHODS

After completing a 12-week randomized, double-blind, placebo-controlled, factorial, 10-armed study comparing ezetimibe 10 mg/simvastatin 10, 20, 40, or 80 mg; simvastatin 10, 20, 40, or 80 mg; ezetimibe 10 mg; or placebo, 768 patients entered a 48-week extension, with randomized, blinded, reassignment of the simvastatin 10 mg, ezetimibe, and placebo groups to one of the ezetimibe/simvastatin groups. Patients previously receiving ezetimibe/simvastatin combination therapy, or simvastatin 20, 40, and 80 mg monotherapy continued the same therapies in this 7-arm extension study. During the extension study, investigators assessed adverse events (AEs).

MAIN OUTCOME MEASURES AND RESULTS

Ezetimibe/simvastatin (n = 539) and simvastatin monotherapy (n = 229) groups generally had a similar incidence of all clinical AEs (73 vs. 69%), treatment-related AEs (14 vs. 11%), clinical serious AEs (SAE) (5.2 vs. 2.6%), treatment-related SAEs (0.2 vs. 0%), discontinuations due to all clinical AEs (4.5 vs. 2.6%) and discontinuations due to treatment-related AEs (2.8 vs. 2.2%), respectively. The incidence of total laboratory-related AEs for the ezetimibe/simvastatin and simvastatin monotherapy groups was also similar (12.2 vs. 11.9%), as was treatment-related laboratory AEs (6.2 vs. 5.3%), laboratory SAEs (0 vs. 0%), treatment-related laboratory SAEs (0 vs. 0%), discontinuations due to laboratory AEs (3.0 vs. 0.9%) and discontinuations due to treatment-related laboratory AEs (3.0 vs. 0.4%), respectively. There were no cases of myopathy, rhabdomyolysis, or serious hepatotoxicity observed in any group during this extension study.

CONCLUSIONS

During this 48-week extension study, the coadministration of ezetimibe/simvastatin was generally as well tolerated as simvastatin monotherapy. The direct application of study observations to clinical practice is limited by patient selection criteria and dosage regime, which randomly applied relatively high doses rather than titration which often occurs in clinical practice.