Efficacy and safety of a new hydroxymethylglutaryl-coenzyme A reductase inhibitor, atorvastatin, in patients with combined hyperlipidemia: comparison with fenofibrate

Use of Fibrates Monotherapy in People with Diabetes and High Cardiovascular Risk in Primary Care: A French Nationwide Cohort Study Based on National Administrative Databases

Background and Aim

According to guidelines, diabetic patients with high cardiovascular risk should receive a statin. Despite this consensus, fibrate monotherapy is commonly used in this population. We assessed the frequency and clinical consequences of the use of fibrates for primary prevention in patients with diabetes and high cardiovascular risk.

Design

Retrospective cohort study based on nationwide data from the medical and administrative databases of French national health insurance systems (07/01/08-12/31/09) with a follow-up of up to 30 months.

Methods

Lipid-lowering drug-naive diabetic patients initiating fibrate or statin monotherapy were identified. Patients at high cardiovascular risk were then selected: patients with a diagnosis of diabetes and hypertension, and >50 (men) or 60 (women), but with no history of cardiovascular events. The composite endpoint comprised myocardial infarction, stroke, amputation, or death.

Results

Of the 31,652 patients enrolled, 4,058 (12.8%) received a fibrate. Age- and gender-adjusted annual event rates were 2.42% (fibrates) and 2.21% (statins). The proportionality assumption required for the Cox model was not met for the fibrate/statin variable. A multivariate model including all predictors was therefore calculated by dividing data into two time periods, allowing Hazard Ratios to be calculated before (HR_<540) and after 540 days (HR_>540) of follow-up. Multivariate analyses showed that fibrates were associated with an increased risk for the endpoint after 540 days: HR_<540 = 0.95 (95% CI: 0.78–1.16) and HR_>540 = 1.73 (1.28–2.32).

Conclusion

Fibrate monotherapy is commonly prescribed in diabetic patients with high cardiovascular risk and is associated with poorer outcomes compared to statin therapy.

Lipid-lowering efficacy of atorvastatin

BACKGROUND

This represents the first update of this review, which was published in 2012. Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

Primary objective To quantify the effects of various doses of atorvastatin on serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides in individuals with and without evidence of cardiovascular disease. The primary focus of this review was determination of the mean per cent change from baseline of LDL-cholesterol. Secondary objectives • To quantify the variability of effects of various doses of atorvastatin.• To quantify withdrawals due to adverse effects (WDAEs) in placebo-controlled randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2013), MEDLINE (1966 to December Week 2 2013), EMBASE (1980 to December Week 2 2013), Web of Science (1899 to December Week 2 2013) and BIOSIS Previews (1969 to December Week 2 2013). We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of three to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included and extracted data. We collected information on withdrawals due to adverse effects from placebo-controlled trials.

MAIN RESULTS

In this update, we found an additional 42 trials and added them to the original 254 studies. The update consists of 296 trials that evaluated dose-related efficacy of atorvastatin in 38,817 participants. Included are 242 before-and-after trials and 54 placebo-controlled RCTs. Log dose-response data from both trial designs revealed linear dose-related effects on blood total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. The Summary of findings table 1 documents the effect of atorvastatin on LDL-cholesterol over the dose range of 10 to 80 mg/d, which is the range for which this systematic review acquired the greatest quantity of data. Over this range, blood LDL-cholesterol is decreased by 37.1% to 51.7% (Summary of findings table 1). The slope of dose-related effects on cholesterol and LDL-cholesterol was similar for atorvastatin and rosuvastatin, but rosuvastatin is about three-fold more potent. Subgroup analyses suggested that the atorvastatin effect was greater in females than in males and was greater in non-familial than in familial hypercholesterolaemia. Risk of bias for the outcome of withdrawals due to adverse effects (WDAEs) was high, but the mostly unclear risk of bias was judged unlikely to affect lipid measurements. Withdrawals due to adverse effects were not statistically significantly different between atorvastatin and placebo groups in these short-term trials (risk ratio 0.98, 95% confidence interval 0.68 to 1.40).

AUTHORS' CONCLUSIONS

This update resulted in no change to the main conclusions of the review but significantly increases the strength of the evidence. Studies show that atorvastatin decreases blood total cholesterol and LDL-cholesterol in a linear dose-related manner over the commonly prescribed dose range. New findings include that atorvastatin is more than three-fold less potent than rosuvastatin, and that the cholesterol-lowering effects of atorvastatin are greater in females than in males and greater in non-familial than in familial hypercholesterolaemia. This review update does not provide a good estimate of the incidence of harms associated with atorvastatin because included trials were of short duration and adverse effects were not reported in 37% of placebo-controlled trials.

Effects of atorvastatin 10 mg and fenofibrate 200 mg on the low-density lipoprotein profile in dyslipidemic patients: A 12-week, multicenter, randomized, open-label, parallel-group study

BACKGROUND

Elevated plasma low-density lipoprotein cholesterol (LDL-C) concentrations are highly atherogenic, especially the small, dense LDL (sdLDL) species. Fenofibrate has been reported to shift the LDL profile by decreasing the sdLDL subfraction and increasing larger LDL subclasses. Atorvastatin, anantihyperlipidemic agent, has been reported to reduce plasma total cholesterol (TC) and triglyceride (TG) concentrations and thus could modify the LDL profile.

OBJECTIVE

The aim of this study was to compare the effects of fenofi brate and atorvastatin on standard lipid concentrations and the LDL profile.

METHODS

In this randomized, open-label, parallel-group study, men and women aged 18 to 79 years with type II primary dyslipidemia, defined as LDL-C ≥160 and TG 150 to 400 mg/dL, after a 4- to 6-week washout period while eating an appropriate diet, were randomized to receive either atorvastatin 10 mg once daily or fenofi-brate 200 mg once daily. Plasma lipid concentrations and cholesterol and apolipoprotein (apo) B (reflecting the LDL particle number) in each LDL subfraction prepared by ultracentrifiigation were determined at baseline and after 12 weeks of treatment. Tolerability was assessed using adverse events (AEs) obtained on laboratory analysis and vital sign measurement. Adherence was assessed by counting unused drug supplies.

RESULTS

A total of 165 patients (117 men, 48 women; mean [SD] age, 50.1 [10.7] years; mean TC concentration, 289 mg/dL) were randomized to receive atorvastatin (n = 81) or fenofibrate (n = 84). Compared with fenofibrate, atorvastatin was associated with a significantly greater mean (SD) percentage decrease in TC (27.0% [12.3%] vs 16.5% [12.9%]; P < 0.001), calculated LDL-C (35.4% [15.8%] vs 17.3% [17.2%]; P < 0.001), TC/high-density lipoprotein cholesterol (HDL-C) ratio (29.1% [16.3%] vs 22.9% [15.9%]; P = 0.001), and apoB (30.3% [12.7%] vs 19.6% [15.5%]; P < 0.001). Compared with atorvastatin, fenofibrate was associated with a significantly greater decrease in TG (37.2% [25.9%] vs 20.2% [27.3%]; P < 0.001) and a significantly greater increase in HDL-C concentration (10.4% [15.7%] vs 4.6% [12.1%]; P = 0.017). Fibrinogen concentration was significantly different between the 2 groups (P = 0.002); it was decreased with fenofibrate use (4.6% [23.7%]) and was increased with atorvastatin use (5.7% [23.5%]). Atorvastatin did not markedly affect the LDL distribution; it was associated with a homogeneous decrease in cholesterol and apoB concentrations in all subfractions, whereas fenofibrate was associated with a marked movement toward a normalized LDL profile, shifting the sdLDL subfractions toward larger and less atherogenic particles, particularly in those patients with baseline TG ≥200 mg/dL. No serious AEs related to the study treatments were reported. A total of 5 AEs were observed in 8 patients, including: abdominal pain, 3 patients (2 in the atorvastatin group and 1 in the fenofibrate group); abnormal liver function test results, 1 (fenofibrate); increased creatine Phosphokinase activity, 2 (atorvastatin); gastrointestinal disorders, 1 (fenofibrate); and vertigo, 1 (fenofibrate).

CONCLUSION

In these dyslipidemic patients, fenofibrate treatment was associated with an improved LDL subfraction profile beyond reduction in LDL-C, particularly in patients with elevated TG concentration, whereas atorvastatin was associated with equally reduced concentrations of cholesterol and apoB in all LDL subfractions independent of TG concentrations.

Lipid lowering efficacy of atorvastatin

BACKGROUND

Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

To quantify the dose-related effects of atorvastatin on blood lipids and withdrawals due to adverse effects (WDAE).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 4, 2011, MEDLINE (1966 to November 2011), EMBASE (1980 to November 2011), ISI Web of Science (1899 to November 2011) and BIOSIS Previews (1969 to November 2011). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of 3 to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. WDAE information was collected from the placebo-controlled trials.

MAIN RESULTS

Two hundred fifty-four trials evaluated the dose-related efficacy of atorvastatin in 33,505 participants. Log dose-response data revealed linear dose-related effects on blood total cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides. Combining all the trials using the generic inverse variance fixed-effect model for doses of 10 to 80 mg/day resulted in decreases of 36% to 53% for LDL-cholesterol. There was no significant dose-related effects of atorvastatin on blood high-density lipoprotein (HDL)-cholesterol. WDAE were not statistically different between atorvastatin and placebo for these short-term trials (risk ratio 0.99; 95% confidence interval 0.68 to 1.45).

AUTHORS' CONCLUSIONS

Blood total cholesterol, LDL-cholesterol and triglyceride lowering effect of atorvastatin was dependent on dose. Log dose-response data was linear over the commonly prescribed dose range. Manufacturer-recommended atorvastatin doses of 10 to 80 mg/day resulted in 36% to 53% decreases of LDL-cholesterol. The review did not provide a good estimate of the incidence of harms associated with atorvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 37% of the placebo-controlled trials.

Efficacy, safety and tolerability of combined low-dose simvastatin-fenofibrate treatment in primary mixed hyperlipidaemia

OBJECTIVE

In order to assess the long-term (12 months) efficacy and safety of fenofibrate administered with simvastatin in the treatment of primary mixed hyperlipidaemia, we conducted a study that compared increasing dosages of these drugs in subgroups of men and women belonging to a clinical sample of out-patients.

DESIGN

This was an open study carried out in patients with primary mixed hyperlipidaemia (lipoprotein phenotype IIb) who needed a combined therapeutic approach because of their poor response to a single-drug regimen with an HMG-CoA reductase inhibitor (simvastatin). Thus, a fibrate (fenofibrate) was added to the therapy. The study lasted 12 months.

PATIENTS

Forty-five patients (mean age: 58.9 +/- 11.3 years) with primary mixed hyperlipidaemia who showed a poor response to the single-drug hypolipidaemic treatment were enrolled. Their average plasma triglyceride level was consistently above 300 mg/dL and low-density lipoprotein cholesterol (LDL-C) was over 160 mg/dL after at least 6 months of a single hypolipidaemic drug (simvastatin) regimen plus antiatherogenic dietary treatment.

INTERVENTIONS

Five patients received simvastatin 10mg once daily in addition to fenofibrate 200mg; 26 patients received simvastatin 20mg once daily plus fenofibrate 200mg; 11 patients received simvastatin 20mg once daily plus fenofibrate 300mg; and three patients received simvastatin 30mg once daily plus fenofibrate 200mg. The patients were allocated to treatment groups on the basis of their relative response to the therapy. Those making up the progressively higher agent/dose groups were the individuals at higher cardiovascular risk according to the total cholesterol and non-high-density lipoprotein cholesterol (HDL-C) values.

RESULTS

The double-drug regimen given for 12 months to four different groups, according to the different combined dosages of simvastatin and fenofibrate, resulted in a reduction in total cholesterol of 18% (p </= 0.05) to 39% (p </= 0.05), in LDL-C of 21% (not significant) to 39% (p </= 0.05) and in triglycerides of 35% (p </= 0.05) to 56% (p </= 0.01), and an increase in HDL-C of 8% (p </= 0.05) to 30% (not significant). The cardiovascular risk ratio (total cholesterol/HDL-C) at the end of the study was reduced by 33-60%, whereas the non-HDL-C decreased by 25-38%. No serious adverse effects were reported by the patients. Neither liver biochemistry nor creatine kinase serum concentration were significantly changed. Discontinuation of treatment, if necessary, in case of the occurrence of clinically subjective or objective evidence of adverse effects was assured.

CONCLUSION

The results confirmed the efficacy of the combination of fenofibrate and simvastatin. The combined therapeutic approach was shown to be safe for the treatment of primary mixed hyperlipidaemia, at least in patients with normal hepatic and renal function.

Dyslipidaemia of obesity, metabolic syndrome and type 2 diabetes mellitus: the case for residual risk reduction after statin treatment

Dyslipidaemia is frequently present in obesity, metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM). The predominant features of dyslipidaemia in these disorders include increased flux of free fatty acids (FFA), raised triglyceride (TG) and low high density lipoprotein cholesterol (HDL-C) levels, a predominance of small, dense (atherogenic) low density lipoprotein cholesterol (LDL) particles and raised apolipoprotein (apo) B values Posprandial hyperlipidaemia may also be present. Insulin resistance (IR) appears to play an important role in the pathogenesis of dyslipidaemia in obesity, MetS and T2DM. The cornerstone of treatment of this IR-related dyslipidaemia is lifestyle changes and in diabetic patients, tight glycaemic control. In addition to these measures, recent clinical trials showed benefit with statin treatment. Nevertheless, a substantial percentage of patients treated with statins still experience vascular events. This residual vascular risk needs to be addressed. This review summarizes the effects of hypolipidaemic drug combinations (including statins with cholesterol ester protein inhibitors, niacin, fibrates or fish oil, as well as fibrate-ezetimibe combination) on the residual vascular risk in patients with obesity, MetS or T2DM.

Atorvastatin and fenofibrate increase apolipoprotein AV and decrease triglycerides by up-regulating peroxisome proliferator-activated receptor-alpha

BACKGROUND AND PURPOSE

Combining statin and fibrate in clinical practice provides a greater reduction of triglycerides than either drug given alone, but the mechanism for this effect is poorly understood. Apolipoprotein AV (apoAV) has been implicated in triglyceride metabolism. This study was designed to investigate the effect of the combination of statin and fibrate on apoAV and the underlying mechanism(s).

EXPERIMENTAL APPROACH

Hypertriglyceridaemia was induced in rats by giving them 10% fructose in drinking water for 2 weeks. They were then treated with atorvastatin, fenofibrate or the two agents combined for 4 weeks, and plasma triglyceride and apoAV measured. We also tested the effects of these two agents on triglycerides and apoAV in HepG2 cells in culture. Western blot and reverse transcription polymerase chain reaction was used to measure apoAV and peroxisome proliferator-activated receptor-alpha (PPARalpha) expression.

KEY RESULTS

The combination of atorvastatin and fenofibrate resulted in a greater decrease in plasma triglycerides and a greater increase in plasma and hepatic apoAV than either agent given alone. Hepatic expression of the PPARalpha was also more extensively up-regulated in rats treated with the combination. A similar, greater increase in apoAV and a greater decrease in triglycerides were observed following treatment of HepG2 cells pre-exposed to fructose), with the combination. Adding an inhibitor of PPARalpha (MK886) abolished the effects of atorvastatin on HepG2 cells.

CONCLUSIONS AND IMPLICATIONS

A combination of atorvastatin and fenofibrate increased apoAV and decreased triglycerides through up-regulation of PPARalpha.

Cardiovascular disease and lipids

The commonest manifestations of cardiovascular disease, namely coronary heart disease (CHD) and stroke, represent the two most common causes of death in the world today. Furthermore, cardiovascular diseases have the highest healthcare utilisation costs in most countries. Both primary and secondary prevention management strategies are essential. Although more than 200 risk factors for CHD have now been identified, the single most powerful predictor of CHD risk is abnormal lipid levels. The relative risk influences of the various lipid sub-fractions are described, with particular emphasis on LDL cholesterol, which represents the principal target for treatment in most management guidelines. Unfortunately, there remains considerable evidence of continued under-management of patients with elevated cholesterol and cardiovascular risk who are eligible for secondary prevention. The barriers contributing to such physician under-performance are numerous. The more recent recognition of the importance of identifying patients at enhanced risk, but without established disease (primary prevention), will require greatly familiarity with the clinical use of CHD risk scoring systems, most of which are based upon the Framingham equation. Special reference is made to groups at particular risk of CHD. In summary, the application of the enormous evidence-base for interventions in cardiovascular disease, especially over the treatment of elevated cholesterol, pose a huge challenge to primary and secondary care in most healthcare systems.

Switching fibrate to statin in type 2 diabetic patients: consequences on lipid profile

Interest of statins in terms of morbid-mortality reduction in primary and secondary prevention in type 2 diabetic patients has broadly been proven in recent studies, while evidence for fibrates preventive effect is considerably weaker. HMGCoA reductase inhibitors are known to decrease low density lipoprotein cholesterol (LDL C) in a greater extension than triglycerides (TG). In type 2 diabetic patients, the dyslipidemic profile is commonly associated with reduced high-density lipoproteins (HDL C), increased TG and normal or mildly elevated LDL C.

PATIENTS AND METHODS

Type 2 diabetic outpatients (n=45) treated with fibrate with or without history of cardiovascular disease were included. Mean age was 57.7+/-13.2 yr, sex ratio was 16/39 (F/M), and BMI was 29.3+/-4.4 kg/m(2). Non-inclusion criteria were TG>or=3.5 g/L and intolerance to statins or a combined lowering lipid therapy. Serum lipid profile, HbA(1c) and creatin kinase (CK) were assessed under treatment with fibrate, then after a 3-month wash-out period, and after a 6-month treatment with a low dose of atorvastatin (10 mg/day).

RESULTS

After a 3-month wash-out period, total cholesterol (TC) was 1.98+/-0.31 g/L (m+/-SD), TG 1.63+/-1.09 g/L, HDL C 0.46+/-0.12 g/L, and LDL C 1.22+/-0.31 g/L. Comparing lipid profile with atorvastatin vs fibrate, we observed a significant decrease in TC and LDL C (1.56 vs 1.79 g/L P=0.001, and 0.84 vs 1.09 g/L, P=0.001, respectively). No significant difference between treatments was observed for TG (1.35 vs 1.17 g/L, P=0.06), and HDL C (0.44 vs 0.48 g/L, P=0.15). When treated with atorvastatin, 90% of patients achieved a LDL C<1 g/L, compared to 51% when treated with fibrate (P=0.001). HbA(1c) remained about 7.6+/-1.5%, and CK in the normal range.

CONCLUSION

In well-controlled type 2 diabetic patients previously treated with fibrate, short-term (6 months) treatment with low-dose atorvastatin (10 mg/day) improves TC and LDL C levels, without any alteration in TG and HDL C levels.

The Residual Risk Reduction Initiative: a call to action to reduce residual vascular risk in dyslipidaemic patient

Despite current standards of care aimed at achieving targets for low-density lipoprotein (LDL) cholesterol, blood pressure and glycaemia, dyslipidaemic patients remain at high residual risk of vascular events. Atherogenic dyslipidaemia, specifically elevated triglycerides and low levels of high-density lipoprotein (HDL) cholesterol, often with elevated apolipoprotein B and non-HDL cholesterol, is common in patients with established cardiovascular disease, type 2 diabetes, obesity or metabolic syndrome and is associated with macrovascular and microvascular residual risk. The Residual Risk Reduction Initiative (R3I) was established to address this important issue. This position paper aims to highlight evidence that atherogenic dyslipidaemia contributes to residual macrovascular risk and microvascular complications despite current standards of care for dyslipidaemia and diabetes, and to recommend therapeutic intervention for reducing this, supported by evidence and expert consensus. Lifestyle modification is an important first step. Additionally, pharmacotherapy is often required. Adding niacin, a fibrate or omega-3 fatty acids to statin therapy improves achievement of all lipid risk factors. Outcomes studies are evaluating whether these strategies translate to greater clinical benefit than statin therapy alone. In conclusion, the R3I highlights the need to address with lifestyle and/or pharmacotherapy the high level of residual vascular risk among dyslipidaemic patients who are treated in accordance with current standards of care.

Atorvastatin and fenofibrate have comparable effects on VLDL-apolipoprotein C-III kinetics in men with the metabolic syndrome

OBJECTIVE

The metabolic syndrome (MetS) is characterized by insulin resistance and dyslipidemia that may accelerate atherosclerosis. Disturbed apolipoprotein (apo) C-III metabolism may account for dyslipidemia in these subjects. Atorvastatin and fenofibrate decrease plasma apoC-III, but the underlying mechanisms are not fully understood.

METHODS AND RESULTS

The effects of atorvastatin (40 mg/d) and fenofibrate (200 mg/d) on the kinetics of very-low density lipoprotein (VLDL)-apoC-III were investigated in a crossover trial of 11 MetS men. VLDL-apoC-III kinetics were studied, after intravenous d(3)-leucine administration using gas chromatography-mass spectrometry and compartmental modeling. Compared with placebo, both atorvastatin and fenofibrate significantly decreased (P<0.001) plasma concentrations of triglyceride, apoB, apoB-48, and total apoC-III. Atorvastatin, not fenofibrate, significantly decreased plasma apoA-V concentrations (P<0.05). Both agents significantly increased the fractional catabolic rate (+32% and +30%, respectively) and reduced the production rate of VLDL-apoC-III (-20% and -24%, respectively), accounting for a significant reduction in VLDL-apoC-III concentrations (-41% and -39%, respectively). Total plasma apoC-III production rates were not significantly altered by the 2 agents. Neither treatment altered insulin resistance and body weight.

CONCLUSIONS

Both atorvastatin and fenofibrate have dual regulatory effects on VLDL-apoC-III kinetics in MetS; reduced production and increased fractional catabolism of VLDL-apoC-III may explain the triglyceride-lowering effect of these agents.

Atorvastatin monotherapy vs. combination therapy in the management of patients with combined hyperlipidemia

BACKGROUND

Mixed hyperlipidemia is a common disorder characterized by elevated VLDL and LDL levels. Patients with this syndrome usually are in need of combination therapy, comprising a fibric acid derivate with a statin drug in order to achieve LDL and triglyceride target values. Atorvastatin is a hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor demonstrated to be effective in reducing both cholesterol (CHOL) and triglyceride (TG) levels in humans. We examined the efficacy of atorvastatin as monotherapy in achieving a better or the same lipid profile in patients with mixed hyperlipidemia treated with combination therapy.

DESIGN

We compared atorvastatin with a combination of a fibric acid derivate and a statin drug (other than atorvastatin) in a 24-week, prospective randomized, open-label study of 27 patients with mixed hyperlipidemia.

METHODS

All 27 patients had been treated with statin-fibrate therapy in different regimens for at least a year. Atorvastatin at a daily dose of 20 mg was substituted for statin-fibrate therapy. Lipid and safety profiles were assessed.

RESULTS

Atorvastatin significantly reduced total cholesterol, LDL-C, and HDL-C compared to statin-fibrate therapy. In contrast, TG and glucose levels were significantly elevated with atorvastatin. Target LDL-C and TG was achieved in 10 patients with the single therapy of atorvastatin vs. 6 patients under statin-fibrate. In 16 patients, atorvastatin was at least as effective as, or better than, the combination therapy, and was recommended for continuation of treatment.

CONCLUSION

Atorvastatin is an adequate monotherapy for many mixed hyperlipidemia patients. We recommend atorvastatin be considered for every patient suffering from mixed hyperlipidemia.

Hypolipidemic therapy for the metabolic syndrome

The metabolic syndrome appears to affect a significant proportion of the population and is associated with increased risk for development of cardiovascular disease as well as of type-2 diabetes. No single treatment for the metabolic syndrome as a whole yet exists. While the primary management of patients with the metabolic syndrome involves healthy lifestyle promotion, the atherogenic dyslipidemia is a primary target for cardiovascular disease risk reduction in these patients. Statin therapy provides effective reduction of LDL-cholesterol, which represents the primary therapeutic goal of lipid-lowering therapy in patients at risk for cardiovascular disease. Fibrates in turn are effective in normalizing lipid levels (mainly triglycerides and HDL-cholesterol) in patients with the metabolic syndrome and may improve insulin resistance. Whereas statins remain the drug of choice for patients who need to achieve the LDL-cholesterol goal, fibrate therapy may represent an alternative for those with low HDL-cholesterol and high triglyceride levels. The simultaneous use of fibrates could be indicated in patients whose LDL-cholesterol is controlled by statin therapy but whose HDL-cholesterol and/or triglycerides are still inappropriate. Such a combination, however, needs careful monitoring due to the potential hazard of adverse drug interactions. Nicotinic acid and ezetimibe may be useful agents for therapy, particularly when combined with statins. A number of emerging therapies offer potential as future options for the pharmacological treatment of metabolic syndrome.

Synthesis and biological evaluation of novel propylamine derivatives as orally active squalene synthase inhibitors

Squalene synthase inhibitors are potentially superior hypolipidemic agents. We synthesized novel propylamine derivatives, as well as evaluated their ability to inhibit squalene synthase and their lipid-lowering effects in rats. 1-Allyl-2-[3-(benzylamino)propoxy]-9H-carbazole (YM-75440) demonstrated potent inhibition of the enzyme derived from HepG2 cells with an IC(50) value of 63 nM. It significantly reduced both plasma total cholesterol and plasma triglyceride levels following oral dosing to rats with a reduced tendency to elevate plasma transaminase levels.

Synthesis and Biological Evaluation of Quinuclidine Derivatives Incorporating Phenothiazine Moieties as Squalene Synthase Inhibitors

Squalene synthase inhibitors have the potential to be superior hypocholesterolemic agents. A series of quinuclidine derivatives incorporating phenothiazine systems was synthesized in order to investigate the effects of their structure on the inhibition of hamster liver microsomal enzyme. (+/-)-3-(10-Methyl-10H-phenothiazin-3-ylmethoxy)quinuclidine hydrochloride (19) was the most potent inhibitor in this series with an IC(50) value of 0.12 microM. Oral dosing of compound 19 to hamsters demonstrated effective reduction of both plasma total cholesterol levels and plasma triglyceride levels. Compound 19 showed a reduced tendency to elevate plasma transaminase levels, an indicator of hepatotoxicity. Enantiomerically pure (-)-19, YM-53546, was found to be more potent than the corresponding (+)-enantiomer.

Management of dyslipidemias in the age of statins

Evidence for the effectiveness of lipid-lowering therapy in reducing CHD risk continues to emerge. In primary prevention, clinical trials have demonstrated a benefit for middle-aged, high-risk men with high LDL cholesterol and, more recently, for men and women with "average" LDL and low HDL cholesterol. Although low HDL cholesterol, small dense LDL particles, elevated lipoprotein (a), elevated apolipoprotein B, and the dyslipidemia of the metabolic syndrome pose an increased in CHD risk in some patients, the risk reduction with lipid-lowering therapy has not been fully investigated. The CHD risk of isolated hypertriglyceridemia remains uncertain. Very high triglyceride levels, however, should be treated to prevent pancreatitis. A lipid-lowering diet and other appropriate lifestyle changes constitute safe advice for all patients with dyslipidemia. In initiating pharmacologic therapy, physicians should view potential risk reduction in the context of a patient's overall CHD risk. The selection of particular medications can be individualized, considering effectiveness evidence from clinical trials, lipid-lowering potency, adverse effects, drug interactions, costs, and patient preferences.

Syntheses of 3-ethylidenequinuclidine derivatives as squalene synthase inhibitors. Part 2: enzyme inhibition and effects on plasma lipid levels

Squalene synthase (E.C. 2.5.1.21) is a microsomal enzyme which catalyzes the reductive dimerization of two molecules of farnesyl diphosphate to form squalene, and is involved in the first committed step in cholesterol biosynthesis. It is an attractive target for hypocholesterolemic and hypotriglyceridemic strategies. We synthesized a series of 3-ethylidenequinuclidine derivatives, and evaluated their ability to inhibit squalene synthase in vitro and to lower non-HDL cholesterol levels in hamsters. 3-Ethylidenequinuclidine derivatives incorporating an unsubstituted 9H-carbazole moiety reduced plasma non-HDL cholesterol levels and did not affect plasma transaminase levels, indicating a lack of hepatotoxicity. Among the novel compounds, (Z)-2-[2-(quinuclidin-3-ylidene)ethoxy]-9H-carbazole hydrochloride 8 (YM-53579) and (E)-2-[2-fluoro-2-(quinuclidin-3-ylidene)ethoxy]-9H-carbazole hydrochloride 28 (YM-53601) were potent inhibitors of squalene synthase derived from human hepatoma cells, with IC(50) values of 160 and 79 nM, respectively. They also reduced plasma non-HDL cholesterol levels in hamsters by approximately 50 and 70%, respectively, at an oral dose of 50 mg/kg/day for 5 days.

Comparison of the dose-response relationships of 2 lipid-lowering agents: a Bayesian meta-analysis

BACKGROUND

Comparing the dose-response of a new drug to that of a previously studied drug can aid in understanding their relative potencies. Two dose-finding studies addressed the effect of a new drug, rosuvastatin, on its ability to decrease low-density lipoprotein cholesterol (LDL-C) levels. One of these studies included 2 doses of atorvastatin, and substantial additional information is available in the literature about the effect of atorvastatin on LDL-C level lowering.

METHODS

The 2 dose-finding studies of rosuvastatin considered otherwise healthy patients who had hypercholesterolemia. Comparable studies of atorvastatin were identified via a MEDLINE search in December 1999. Multiple reviewer consensus identified 15 of 41 studies on atorvastatin published since 1996 that met these selection criteria: reporting of LDL-C level change from baseline at least 6 weeks after treatment initiation, doses administered, and treatment group sizes. Eligible populations had clinical evidence of hypercholesterolemia. We excluded studies with patients who had severe illness or a previous history of transplantation. Data extraction of the mean, sample sizes, and SDs (or CIs) by dose was carried out independently by multiple reviewers. We combined the results from the various studies with Bayesian hierarchical modeling and analyzed them with Markov chain Monte Carlo techniques.

RESULTS

Combining this study and literature results substantially increased the power to compare the dose-response relationships of rosuvastatin and atorvastatin. Rosuvastatin reduced LDL-C level by an estimated 10 to 17 percentage points more than atorvastatin when both were given at the same dose. Approximately one quarter of the dose of rosuvastatin achieved about the same magnitude of LDL-C level reduction as atorvastatin at dosages as high as 80 mg. This finding does not imply a 4-fold difference in efficacy overall and specifically does not describe the results at higher dosage levels.

CONCLUSIONS

Bayesian meta-analysis of results from related studies allows the comparison of the dose-response relationships of 2 drugs, better estimates of a particular dose-response relationship within an individual study, and the expression of relative benefits (of dose and drug) in terms of probabilities. Explicitly comparing a study's results with historical data using Bayesian meta-analysis allows clinicians to view the study in the larger context of medical research.

Atorvastatin versus Bezafibrate in Mixed Hyperlipidaemia : Randomised Clinical Trial of Efficacy and Safety (the ATOMIX Study)

OBJECTIVE

Combined hyperlipidaemia is a common and highly atherogenic lipid phenotype with multiple lipoprotein abnormalities that are difficult to normalise with single-drug therapy. The ATOMIX multicentre, controlled clinical trial compared the efficacy and safety of atorvastatin and bezafibrate in patients with diet-resistant combined hyperlipidaemia.

PATIENTS AND STUDY DESIGN

Following a 6-week placebo run-in period, 138 patients received atorvastatin 10mg or bezafibrate 400mg once daily in a randomised, double-blind, placebo-controlled trial. To meet predefined low-density lipoprotein-cholesterol (LDL-C) target levels, atorvastatin dosages were increased to 20mg or 40mg once daily after 8 and 16 weeks, respectively.

RESULTS

After 52 weeks, atorvastatin achieved greater reductions in LDL-C than bezafibrate (percentage decrease 35 vs 5; p < 0.0001), while bezafibrate achieved greater reductions in triglyceride than atorvastatin (percentage decrease 33 vs 21; p < 0.05) and greater increases in high-density lipoprotein-cholesterol (HDL-C) [percentage increase 28 vs 17; p < 0.01 ]. Target LDL-C levels (according to global risk) were attained in 62% of atorvastatin recipients and 6% of bezafibrate recipients, and triglyceride levels <200 mg/dL were achieved in 52% and 60% of patients, respectively. In patients with normal baseline HDL-C, bezafibrate was superior to atorvastatin for raising HDL-C, while in those with baseline HDL-C <35 mg/dL, the two drugs raised HDL-C to a similar extent after adjustment for baseline values. Both drugs were well tolerated.

CONCLUSION

The results show that atorvastatin has an overall better efficacy than bezafibrate in concomitantly reaching LDL-C and triglyceride target levels in combined hyperlipidaemia, thus supporting its use as monotherapy in patients with this lipid phenotype.

Fenofibrate in the treatment of dyslipidemia: a review of the data as they relate to the new suprabioavailable tablet formulation

BACKGROUND

The fibric acid derivative fenofibrate is indicated as an adjunct to dietary modification in adults with primary hypercholesterolemia or mixed dyslipidemia (types IIa and IIb hyperlipidemia, Fredrickson classification) to reduce levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglycerides (TG), and apolipoprotein (apo) B, and to increase levels of high-density lipoprotein cholesterol (HDL-C) and apo A. It is also indicated as adjunctive therapy to diet for the treatment of hypertriglyceridemia (types IV and V hyperlipidemia). Initially approved in the United States in a micronized capsule formulation, fenofibrate is now available in a new "suprabioavailable" tablet formulation that has increased bioavailability, achieving equivalent plasma concentrations at lower doses. The 67- and 200-mg micronized capsules can be considered equivalent to the 54- and 160-mg suprabioavailable tablets, respectively.

OBJECTIVE

This paper reviews the pharmacologic properties, clinical usefulness, and safety profile of fenofibrate in the management of dyslipidemias.

METHODS

Recent studies, abstracts, reviews, and consensus statements published in the English-language literature were identified through searches of MEDLINE (1966-January 2002), International Pharmaceutical Abstracts (1970-January 2002), and PharmaProjects (1990-January 2002) using the search terms fenofibrate, fibrates, hyperlipidemia, hypertriglyceridemia, and dyslipidemia.

RESULTS

Fenofibrate is well absorbed after oral administration, with peak plasma levels attained in 6 to 8 hours. The absolute bioavailability of fenofibrate cannot be determined due to its being virtually insoluble in aqueous media suitable for injection; however, after oral administration of a single dose of radiolabeled fenofibrate, approximately 60% of the dose appeared in urine, primarily as fenofibric acid and its glucuronated conjugate, and approximately 25% was excreted in the feces. The apparent volume of distribution is 0.89 L/kg in healthy volunteers, and protein binding is approximately 99% in healthy and hyperlipidemic patients. Neither fenofibrate nor fenofibric acid appears to undergo significant oxidative metabolism in vivo. Fenofibric acid has a half-life of 20 hours. Fenofibrate is effective in lowering TG levels and increasing HDL-C levels. Its LDL-C-lowering effect is greater than that of gemfibrozil. Adverse effects of fenofibrate appear to be similar to those of other fibrates, including gastrointestinal symptoms, cholelithiasis, hepatitis, myositis, and rash. Fenofibrate therapy has been associated with increases in serum aminotransferase levels, and clinical monitoring of these markers of liver function should be performed regularly.

CONCLUSIONS

Fenofibrate is effective in reducing levels of TG, TC, and LDL-C, and increasing levels of HDL-C in patients with dyslipidemias. Its efficacy and tolerability in the treatment of hypertriglyceridemia and combined hyperlipidemia have been demonstrated in numerous clinical trials. Its use is accompanied by a low incidence of adverse effects and laboratory abnormalities. Fenofibrate protects against coronary heart disease not only through its effects on lipid parameters but also by producing alterations in LDL structure and, possibly, alterations in the various hemostatic parameters. Its uricosuric property may prove to be a useful adjunctive attribute.

Advances in lipid-lowering therapy in atherosclerosis

The accrued evidence that lipid-lowering therapy limits the progression of atherosclerosis and reduces CAD events is overwhelming. The focus has been on LDL-C reduction with statins, but recent evidence also stresses the importance of raising HDL-C and reducing triglyceride-rich lipoproteins (TRL). Treatment should take into account the type of dyslipidemia, combination therapy, drug interactions and pleiotropic effects of drugs (multiple effects in different systems). Statins and fibrates are the most widely prescribed. Fibrates have a major impact on plasma TRL and HDL-C levels. They enhance lipoprotein lipase, apoAI and apoAII transcription and reduce that of apoCIII. The discovery that their multiple actions are in large part mediated by the PPAR alpha pathway is a breakthrough. Fibrates also lower plasma fibrinogen and plasma viscosity but their ability to inhibit smooth muscle cell activation is one of their most promising pleiotropic effects. Statins are safe and potent LDL-C-lowering agents but also lower TRL and raise HDL. Their pleiotropic effects are numerous, and include vasodilatory, anti-thrombotic, antioxidant, anti-proliferative, anti-inflammatory and plaque stabilizing properties. Many findings make a case for their early use in CAD to improve myocardial perfusion after a myocardial infarction, and they are indicated in heart transplant recipients to improve survival and reduce graft rejection. Fibrates and statins have complementary lipid modifying and pleiotropic effects so that their combination, carried out with caution to avoid potential untoward effects, should provide the highest cardiovascular benefit. This hypothesis is currently being tested in the Lipid in Diabetes Study (LDS), an outcome trial comparing monotherapy with fenofibrate and cerivastatin to combination therapy conducted in England.

Factorial study of the effects of atorvastatin and fish oil on dyslipidaemia in visceral obesity

BACKGROUND

Dyslipidaemia may account for increased risk of cardiovascular disease in central obesity. Pharmacotherapy is often indicated in these patients, but the optimal approach remains unclear. We investigated the effects of atorvastatin and fish oil on plasma lipid and lipoprotein levels, including remnant-like particle-cholesterol and apolipoprotein C-III, in dyslipidaemic men with visceral obesity.

METHODS

We carried out a 6-week randomized, placebo-controlled, 2 x 2 factorial intervention study of atorvastatin (40 mg day(-1)) and fish oil (4 g day(-1)) on plasma lipids and lipoproteins in 52 obese men (age 53 +/- 1 years, BMI 33.7 +/- 0.55 kg m(-2)) with dyslipidaemia and insulin resistance. Treatment effects were analysed by general linear modelling.

RESULTS

Atorvastatin had significant main effects in decreasing triglycerides (-0.38 +/- 0.02 mmol L(-1), P = 0.002), total cholesterol (-1.89 +/- 0.17 mmol L(-1), P = 0.001), LDL-cholesterol (-1.78 +/- 0.14 mmol L(-1), P = 0.001), remnant-like particle-cholesterol (-0.08 +/- 0.04 mmol L(-1), P = 0.035), apolipoprotein B (-49 +/- 4 mg dL(-1), P = 0.001), apolipoprotein C-III (-12.6 +/- 6.1 mg L(-1), P = 0.044) and in increasing HDL-cholesterol (+0.10 +/0- 0.04 mmol L(-1), P = 0.007). Fish oil had significant main effects in decreasing triglycerides (-0.38 +/- 0.11 mmol L(-1), P = 0.002) and in increasing HDL-cholesterol (+0.07 +/- 0.04 mmol L(-1), P = 0.041). There were no significant changes in weight or insulin resistance during the study.

CONCLUSIONS

Atorvastatin and fish oil have independent and additive effects in correcting dyslipidaemia in viscerally obese men. Improvement in abnormalities in remnant lipoproteins may occur only with use of atorvastatin. Combination treatment with statin and fish oil may, however, offer an optimal therapeutic approach for globally correcting dyslipidaemia in obesity.

Effects of micronized fenofibrate versus atorvastatin in the treatment of dyslipidaemic patients with low plasma HDL-cholesterol levels: a 12-week randomized trial

BACKGROUND

Studies have suggested that raising low levels of high-density lipoprotein cholesterol (HDL-C) may be an important target for the prevention of coronary heart disease.

OBJECTIVE

To compare the ability of micronized fenofibrate and atorvastatin to increase plasma HDL-C levels.

DESIGN

Multicentre, randomized open-label study. Settings. The study was conducted in 19 centres across the UK and Canada.

SUBJECT

One hundred and eighty-one patients were randomized and the full analysis set included 165 nondiabetic patients with low HDL-C (women <46 mg dL-1, i.e. 1.2 mmol L-1 and men <43 mg dL-1, i.e. 1.1 mmol L-1): 86 patients in the atorvastatin group and 79 patients in the micronized fenofibrate group. Interventions. Micronized fenofibrate (200 mg day-1, 87 patients) or atorvastatin (10 mg day-1, 94 patients) for a period of 12 weeks. Main outcome measures. Percent change in HDL-C levels.

RESULT

After 12 weeks of treatment, the mean percent change from baseline in HDL-C was significantly higher in the micronized fenofibrate group (13.3%) compared with the atorvastatin group (5.3%, P=0.0003). The magnitude of such relative change was inversely related to the baseline HDL-C levels only in the micronized fenofibrate group. Furthermore, in the fenofibrate treatment group, 50.9% of the patients (29 of 57 patients) with a baseline HDL-C <40 mg dL-1 achieved a plasma HDL-C level above 40 mg dL-1 after 12 weeks of treatment versus 27.9% of the patients (19 of 68 patients) in the atorvastatin group (P=0.01).

CONCLUSIONS

On the basis of (1) the greater impact of fenofibrate than atorvastatin on HDL-C levels and (2) the greater proportion of dyslipidemic patients achieving HDL-C levels above 40 mg dL-1 with fenofibrate than atorvastatin, it is suggested that micronized fenofibrate should be considered as a good therapeutic option to treat dyslipidemic patients with low HDL-C and moderately elevated LDL-C concentrations.

Atorvastatin: an updated review of its pharmacological properties and use in dyslipidaemia

Atorvastatin is a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. In dosages of 10 to 80 mg/day, atorvastatin reduces levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride and very low-density lipoprotein (VLDL)-cholesterol and increases high-density lipoprotein (HDL)-cholesterol in patients with a wide variety of dyslipidaemias. In large long-term trials in patients with primary hypercholesterolaemia. atorvastatin produced greater reductions in total cholesterol. LDL-cholesterol and triglyceride levels than other HMG-CoA reductase inhibitors. In patients with coronary heart disease (CHD), atorvastatin was more efficacious than lovastatin, pravastatin. fluvastatin and simvastatin in achieving target LDL-cholesterol levels and, in high doses, produced very low LDL-cholesterol levels. Aggressive reduction of serum LDL-cholesterol to 1.9 mmol/L with atorvastatin 80 mg/day for 16 weeks in patients with acute coronary syndromes significantly reduced the incidence of the combined primary end-point events and the secondary end-point of recurrent ischaemic events requiring rehospitalisation in the large. well-designed MIRACL trial. In the AVERT trial, aggressive lipid-lowering therapy with atorvastatin 80 mg/ day for 18 months was at least as effective as coronary angioplasty and usual care in reducing the incidence of ischaemic events in low-risk patients with stable CHD. Long-term studies are currently investigating the effects of atorvastatin on serious cardiac events and mortality in patients with CHD. Pharmacoeconomic studies have shown lipid-lowering with atorvastatin to be cost effective in patients with CHD, men with at least one risk factor for CHD and women with multiple risk factors for CHD. In available studies atorvastatin was more cost effective than most other HMG-CoA reductase inhibitors in achieving target LDL-cholesterol levels. Atorvastatin is well tolerated and adverse events are usually mild and transient. The tolerability profile of atorvastatin is similar to that of other available HMG-CoA reductase inhibitors and to placebo. Elevations of liver transaminases and creatine phosphokinase are infrequent. There have been rare case reports of rhabdomyolysis occurring with concomitant use of atorvastatin and other drugs.

CONCLUSION

Atorvastatin is an appropriate first-line lipid-lowering therapy in numerous groups of patients at low to high risk of CHD. Additionally it has a definite role in treating patients requiring greater decreases in LDL-cholesterol levels. Long-term studies are under way to determine whether achieving very low LDL-cholesterol levels with atorvastatin is likely to show additional benefits on morbidity and mortality in patients with CHD.

Increasing high-density lipoprotein cholesterol: an update on fenofibrate

The inverse relation between coronary artery disease and the concentration of high-density lipoprotein cholesterol (HDL-C) is well established. A low HDL-C concentration is frequently accompanied by the features of the metabolic syndrome found in patients with type 2 diabetes and in individuals who are abdominally obese. Results from 3 independent trials are consistent in showing that fenofibrate is able to increase HDL-C levels across a wide range of dyslipidemic states. The HDL-C-increasing effect of fenofibrate is proportionately greater when baseline levels are low. Comparing results from published trials, the absolute increase in HDL-C produced by fenofibrate is greater than that with statins across all baseline HDL-C levels, and a 40-mg/dL treatment target HDL-C level is more likely to be achieved with fenofibrate therapy. Fenofibrate has favorable pleiotropic effects on several features of the metabolic syndrome, which are likely to explain the clinical benefits of fibrate therapy, beyond an impact on HDL-C levels. The additional reciprocal beneficial effect of fenofibrate in lowering low-density lipoprotein cholesterol (LDL-C) benefits those patients with low HDL-C and moderately increased LDL-C; the American Diabetes Association now recommends fibrate therapy in this case. Another trial, the Diabetes Atherosclerosis Intervention Study (DAIS) has also provided angiographic evidence to show that fenofibrate treatment may slow coronary artery disease progression in type 2 diabetes. Treatment effects on apolipoproteins suggest that not all fibrates affect HDL-C to an equal degree. A trial with fenofibrate focusing on coronary artery disease risk and mortality reduction in patients with type 2 diabetes that is currently under way, the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial is expected to report in 2005.

Asessing coronary heart disease risk and managing lipids

Elevated low-density lipoprotein (LDL) and below normal high-density lipoprotein (HDL) cholesterol are risk factors for coronary heart disease (CHD). According to clinical guidelines, LDL cholesterol is the primary target for lipid-altering therapy. Many patients who develop CHD have LDL and HDL cholesterol levels that fall within the desirable or low-risk category; consequently, conventional measurements of plasma lipids may not accurately detect high-risk patients. This article discusses the clinical significance of lipoprotein subclasses and methods of measurement. Assessing lipoprotein subclasses provides a more comprehensive and efficacious therapeutic approach compared with the standard lipid profile.

A double-blind trial on the effects of atorvastatin on glycemic control in Japanese diabetic patients with hypercholesterolemia

A double-blind, placebo-controlled, parallel-group study was performed to determine whether atorvastatin, a new HMG-CoA reductase inhibitor, could effectively and safely reduce plasma LDL-cholesterol concentrations in Japanese patients with type-2 diabetes without influencing glycemic control. The subjects were patients with hypercholesterolemia (serum cholesterol concentration > or =5.7 mmol/l (220 mg/dl)) and stable glycemic control. The fasting concentrations of hemoglobin A(1C) (HbA(1C)), fructosamine, and 1,5-anhydroglucitol (1,5-AG) were measured as indices of glycemic control. Plasma lipid concentrations and the safety of the drug were also examined. Forty eligible patients in two groups of 20 each were administered atorvastatin (10 mg/day) or placebo. Neither atorvastatin nor placebo caused a significant change in HbA(1C), fructosamine, or 1,5-AG concentrations. Atorvastatin significantly reduced total cholesterol and LDL-cholesterol concentrations from baseline by 29.7% (p<0.0001) and 41.6% (p<0.0001), respectively. The incidence of clinical adverse events and that of abnormal changes in laboratory test values did not differ between the two groups. In this trial, atorvastatin effectively and safely reduced LDL-cholesterol concentrations in diabetic patients with hypercholesterolemia without influencing glycemic control. These findings are clinically important because there are many diabetic patients with hypercholesterolemia and such patients have a high risk of developing arteriosclerotic disease.

Comparison of efficacy and safety of atorvastatin (10mg) with simvastatin (10mg) at six weeks. ASSET Investigators

The 6-week efficacy and safety of atorvastatin versus simvastatin was determined during a 54-week, open-label, multicenter, parallel-arm, treat-to-target study. In all, 1,424 patients with mixed dyslipidemia (triglyceride 200 to 600 mg/dl [2.26 to 6.77 mmol/L]) were stratified to 1 of 2 groups (diabetes or no diabetes). Patients were then randomized to receive either atorvastatin 10 mg/ day (n = 730) or simvastatin 10 mg/day (n = 694). Efficacy was determined by measuring changes from baseline in lipid parameters including low-density lipoprotein (LDL) cholesterol, total cholesterol, triglycerides, and apolipoprotein B. Compared with simvastatin, atorvastatin produced significantly greater (p < 0.0001) reductions from baseline in LDL cholesterol (37.2% vs 29.6%), total cholesterol (27.6% vs 21.5%), triglycerides (22.1% vs 16.0%), the ratio of LDL cholesterol to high-density lipoprotein (HDL) cholesterol (41.1% vs 33.7%), and apolipoprotein B (28.3% vs 21.2%), and a comparable increase from baseline in HDL cholesterol (7.4% vs 6.9%). Atorvastatin was also significantly (p < 0.0001) more effective than simvastatin at treating the overall patient population to LDL cholesterol goals (55.6% vs 38.4%). Fewer than 6% of patients in either treatment group experienced drug-attributable adverse events, which were mostly mild to moderate in nature. Diabetic patients treated with either statin had safety characteristics similar to nondiabetics, with atorvastatin exhibiting superior efficacy to simvastatin. In conclusion, atorvastatin, at a dose of 10 mg/day, is more effective than simvastatin 10 mg/day at lowering lipids and reaching LDL cholesterol goals in patients with mixed dyslipidemia. Both statins are well tolerated with safety profiles similar to other members of the statin class.

YM-53601, a novel squalene synthase inhibitor, reduces plasma cholesterol and triglyceride levels in several animal species

The aim of this study was to evaluate the potency of YM-53601 ((E)-2-[2-fluoro-2-(quinuclidin-3-ylidene) ethoxy]-9H-carbazole monohydrochloride), a new inhibitor of squalene synthase, in reducing both plasma cholesterol and triglyceride levels, compared with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor and fibrates, respectively. YM-53601 equally inhibited squalene synthase activities in hepatic microsomes prepared from several animal species and also suppressed cholesterol biosynthesis in rats (ED(50), 32 mg kg(-1)). In guinea-pigs, YM-53601 and pravastatin reduced plasma nonHDL-C (=total cholesterol - high density lipoprotein cholesterol) by 47% (P<0.001) and 33% (P<0.001), respectively (100 mg kg(-1), daily for 14 days). In rhesus monkeys, YM-53601 decreased plasma nonHDL-C by 37% (50 mg kg(-1), twice daily for 21 days, P<0.01), whereas the HMG-CoA reductase inhibitor, pravastatin, failed to do (25 mg kg(-1), twice daily for 28 days). YM-53601 caused plasma triglyceride reduction in hamsters fed a normal diet (81% decrease at 50 mg kg(-1), daily for 5 days, P<0.001). In hamsters fed a high-fat diet, the ability of YM-53601 to lower triglyceride (by 73%, P<0.001) was superior to that of fenofibrate (by 53%, P<0.001), the most potent fibrate (dosage of each drug: 100 mg kg(-1), daily for 7 days). This is the first report that a squalene synthase inhibitor is superior to an HMG-CoA reductase inhibitor in lowering plasma nonHDL-C level in rhesus monkeys and is superior to a fibrate in significantly lowering plasma triglyceride level. YM-53601 may therefore prove useful in treating hypercholesterolemia and hypertriglyceridemia in humans.

Current, new and future treatments in dyslipidaemia and atherosclerosis

The new therapeutic options available to clinicians treating dyslipidaemia in the last decade have enabled effective treatment for many patients. The development of the HMG-CoA reductase inhibitors (statins) have been a major advance in that they possess multiple pharmacological effects (pleiotropic effects) resulting in potent reductions of low density lipoproteins (LDL) and prevention of the atherosclerotic process. More recently, the newer fibric acid derivatives have also reduced LDL to levels comparable to those achieved with statins, have reduced triglycerides, and gemfibrozil has been shown to increase high density lipoprotein (HDL) levels. Nicotinic acid has been made tolerable with sustained-release formulations, and is still considered an excellent choice in elevating HDL cholesterol and is potentially effective in reducing lipoprotein(a) [Lp(a)] levels, an emerging risk factor for coronary heart disease (CHD). Furthermore, recent studies have reported positive lipid-lowering effects from estrogen and/or progestogen in postmenopausal women but there are still conflicting reports on the use of these agents in dyslipidaemia and in females at risk for CHD. In addition to lowering lipid levels, these antihyperlipidaemic agents may have directly or indirectly targeted thrombogenic, fibrinolytic and atherosclerotic processes which may have been unaccounted for in their overall success in clinical trials. Although LDL cholesterol is still the major target for therapy, it is likely that over the next several years other lipid/lipoprotein and nonlipid parameters will become more generally accepted targets for specific therapeutic interventions. Some important emerging lipid/lipoprotein parameters that have been associated with CHD include elevated triglyceride, oxidised LDL cholesterol and Lp(a) levels, and low HDL levels. The nonlipid parameters include elevated homocysteine and fibrinogen, and decreased endothelial-derived nitric oxide production. Among the new investigational agents are inhibitors of squalene synthetase, acylCoA: cholesterol acyltransferase, cholesteryl ester transfer protein, monocyte-macrophages and LDL cholesterol oxidation. Future applications may include thyromimetic therapy, cholesterol vaccination, somatic gene therapy, and recombinant proteins, in particular, apolipoproteins A-I and E. Non-LDL-related targets such as peroxisome proliferator-activating receptors, matrix metalloproteinases and scavenger receptor class B type I may also have clinical significance in the treatment of atherosclerosis in the near future. Before lipid-lowering therapy, dietary and lifestyle modification is and should be the first therapeutic intervention in the management of dyslipidaemia. Although current recommendations from the US and Europe are slightly different, adherence to these recommendations is essential to lower the risk of atherosclerotic vascular disease, more specifically CHD. New guidelines that are expected in the near future will encompass global opinions from the expert scientific community addressing the issue of target LDL goal (aggressive versus moderate lowering) and the application of therapy for newer emerging CHD risk factors.

Triglyceride, small, dense low-density lipoprotein, and the atherogenic lipoprotein phenotype

This review provides an overview of the recent data evaluating triglyceride and low-density lipoprotein (LDL) size, two highly interrelated, genetically influenced, risk factors for cardiovascular disease (CVD). An examination of new epidemiologic studies continues to demonstrate that plasma triglyceride levels predict CVD. The first prospective study of the familial forms of hypertriglyceridemia has shown that relatives in familial-combined hyperlipidemia families are at increased risk for CVD mortality and that triglyceride levels predicted 20-year, CVD mortality among relatives in familial hypertriglyceridemia families. A meta-analysis of three, large-scale, prospective studies in men, and the first study to examine the correlation of LDL particle size distribution and vascular changes measured by B-mode ultrasound, add to growing evidence that small, dense LDL is atherogenic. Quantitative genetic analysis has recently shown substantial pleiotropic (common) genetic effects on triglyceride and LDL size. At least part of this may be explained by variation at the cholesterol ester transfer protein locus on chromosome 16, possibly through its role in reverse cholesterol transport. Taken together, these data provide new insights into the importance of triglyceride and LDL particle size for understanding genetic susceptibility to cardiovascular disease and its prevention.

Hypolipidemic effect of NK-104, a potent HMG-CoA reductase inhibitor, in guinea pigs

The hypolipidemic effect of NK-104 and its mechanisms of action (effects on hepatic sterol synthesis, low density lipoprotein (LDL)-receptor expression and very low density lipoprotein (VLDL) secretion) were studied in guinea pigs using simvastatin as a reference substance. There was a dose-dependent and significant reduction of both plasma total cholesterol (17.4, 24.5 and 45.3% at 0.3, 1 and 3 mg/kg, respectively) and triglycerides (21.1 and 32.2% at 1 and 3 mg/kg, respectively) after 14-day administration of NK-104. Simvastatin at 30 mg/kg lowered plasma total cholesterol (25.0%) but not triglyceride levels. NK-104 (3 mg/kg) and simvastatin (30 mg/kg) inhibited hepatic sterol synthesis by approximately 80%, 3 h after dosing, and enhanced LDL receptor binding-capacity of liver membranes 1.5-fold after 14-day dosing. The former group accelerated LDL clearance somewhat more markedly than the latter, and increased fractional catabolic rate 1.8-fold (vs. 1.4-fold). Furthermore, only the NK-104 (3 mg/kg) suppressed VLDL secretion into the liver perfusate (triglyceride. 19.9%; apoB, 24.2%) with extensive reduction of hepatic sterol synthesis caused by prolonged action. These results indicate that NK-104 and simvastatin at 10 times the dosage of the former, similarly enhances hepatic LDL receptor; however, only NK-104 with prolonged action suppresses VLDL secretion to show higher cholesterol-lowering potency and triglyceride-reducing effect.

Micronized fenofibrate: a new fibric acid hypolipidemic agent

OBJECTIVE

To review the efficacy and safety of fenofibrate in the management of hyperlipidemias.

DATA SOURCES

A MEDLINE search (1974-October 1998), Current Contents search, additional references from article bibliographies, and the package insert from the manufacturer were used to identify data for evaluation. Studies evaluating fenofibrate (peer-reviewed publications, package insert data) were considered for inclusion. Abstracts and data on file with the manufacturer were not considered for inclusion.

STUDY SELECTION

English-language literature was reviewed to evaluate the pharmacology, pharmacokinetics, clinical use, and tolerability of fenofibrate. Data from animals and in vitro systems were included only when necessary to explain the drug's pharmacology.

DATA SYNTHESIS

Micronized fenofibrate is a fibric acid derivative approved by the Food and Drug Administration (FDA) in February 1998 for the treatment of types IV and V hyperlipidemia. Data from the peer-reviewed literature also support the use of fenofibrate in types IIa, IIb, and III hyperlipidemias. Micronized fenofibrate 67-201 mg/d is useful as monotherapy or as an adjunct to other hypolipidemics and dietary therapy. In placebo-controlled clinical trials, regular formulation fenofibrate 300-400 mg/d lowered serum triglyceride (TG) concentrations by 24-55%, total cholesterol by 9-25%, low-density lipoprotein cholesterol (LDL-C) concentrations by 6-35%, and raised high-density lipoprotein cholesterol (HDL-C) concentrations by 8-38%. Few comparative data exist regarding fenofibrate versus clofibrate and gemfibrozil. In noncomparative and comparative clinical trials, fenofibrate appeared to be well tolerated. The most common causally related adverse events were digestive, musculoskeletal, and dermatologic in nature. Concurrent use of fenofibrate and a hydroxymethylglutaryl-coenzyme A inhibitor may increase the risk of myopathy and/or rhabdomyolysis, although recent data suggest that concurrent use of fenofibrate with low-dose simvastatin or pravastatin is safe. Fenofibrate may enhance the effect of oral anticoagulants.

CONCLUSIONS

Fenofibrate reduces serum TG, total cholesterol, and LDL-C, and raises HDL-C to clinically relevant degrees. Its spectrum of activity appears to exceed that recommended for types IV and V hyperlipidemia to encompass types IIa, IIb, and III hyperlipidemias as well. To this extent, it may be considered a broader-spectrum fibrate than is indicated by its FDA approval. Adverse effects of fenofibrate appear to be similar to those of other fibrates and require routine monitoring (clinical, liver function). Long-term safety data are readily available from drug registries in many countries where the product has been available for nearly two decades. Cost-effectiveness studies comparing fenofibrate with other hypolipidemics demonstrate benefits of fenofibrate over simvastatin in types IIa and IIb hyperlipidemia. The need for dosage titration of the micronized preparation from 67 mg/d upward to a final dose of 200 mg/d is also not supported by peer-reviewed literature (except in the case of renal impairment). Although preliminary data on plaque regression are encouraging, published clinical studies evaluating the impact of fenofibrate on cardiovascular morbidity and mortality are awaited. Micronized fenofibrate is worthy of formulary inclusion.

Identification and treatment of hypertriglyceridemia as a risk factor for coronary heart disease

Recent publications, including new population-based studies and a meta-analysis of prospective, population-based studies, provide strong evidence for an elevated triglyceride level as an independent risk factor for coronary heart disease. Pathophysiologic relationships between elevated triglyceride levels and both reduced high-density lipoprotein levels and an increase in the proportion of low density lipoproteins that are small and dense support the epidemiologic data, and suggest that an elevated triglyceride level should constitute a target for lipid-lowering therapy. There are no clear recommendations for management of patients with hypertriglyceridemia available in the current treatment guidelines. Treatment options include life-style measures and, if drug therapy is required, nicotinic acid, fibrates, more potent 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), or combination therapy with statin plus fibrate or nicotinic acid.

Randomized crossover study of gemfibrozil versus lovastatin in familial combined hyperlipidemia: additive effects of combination treatment on lipid regulation

The most appropriate therapy for combined hyperlipidemia remains to be determined. We compared the lipid-regulating effects of gemfibrozil and lovastatin in 30 patients with familial combined hyperlipidemia (FCHL) in a randomized, double-blind, placebo-controlled crossover study including 8-week courses of one drug followed by a washout period and a crossover phase to the alternate drug. After completion of the trial, open-label combination therapy was given for up to 12 months. Lovastatin was more efficacious than gemfibrozil in the reduction of total cholesterol (23% v. 9%, P<.001) and low-density lipoprotein (LDL) cholesterol (28% v. 2%, P<.001), whereas gemfibrozil surpassed lovastatin in the reduction of triglycerides (48% v. 0%, P<.001) and very-low-density lipoprotein (VLDL) cholesterol (50% v. 19%, P = .005) and the increase of high-density lipoprotein (HDL) cholesterol (18% v. 4%, P = .005). Lovastatin caused a greater decline in total apolipoprotein B (apo B) and LDL apo B than gemfibrozil, whereas VLDL apo B decreased only after gemfibrozil therapy. Drug-induced changes in lipoprotein composition indicated that gemfibrozil reduced both the number and size of VLDL particles and lovastatin decreased the number of LDL particles. Combined treatment was safe and had additive effects on lipids, causing significant (P<.001) reductions in total cholesterol (32%), triglycerides (51%), LDL cholesterol (34%), and apo B (26%) and an increase in HDL cholesterol (19%). Target LDL cholesterol levels were achieved only in 11% of patients given gemfibrozil alone and triglycerides decreased to target levels in 22% after lovastatin alone, whereas combined therapy normalized both lipid fractions in 96% of patients. Thus, in FCHL, gemfibrozil has no effect on LDL cholesterol levels but favorably influences the putative atherogenic alterations of lipoprotein composition that are related to hypertriglyceridemia. Conversely, lovastatin markedly decreases LDL cholesterol but has little effect on triglyceride-rich lipoproteins. Combination treatment safely corrects all of the lipid abnormalities in most patients.

Effect of a new HMG-CoA reductase inhibitor, atorvastatin, on lipids, apolipoproteins and lipoprotein particles in patients with elevated serum cholesterol and triglyceride levels

The effects of atorvastatin (lipitor) on cholesterol-rich and triglyceride-rich lipoproteins were evaluated in this multicenter trial. Following a 6-week baseline period, 47 patients with elevated cholesterol and triglyceride levels were treated with atorvastatin 10 mg once daily (QD) for the initial 12 weeks (Period 1) increasing to 20 mg QD for the following 12 weeks (Period 2). At both the 10 and 20 mg doses, atorvastatin treatment resulted in significant reductions compared to pretreatment levels in low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), very low-density lipoprotein cholesterol (VLDL-C), apolipoprotein (apo) B, apoB in LDL (LDL-apo B), apo B in VLDL (VLDL-apo B), lipoprotein (Lp)B, lipoprotein B-complex (LpBc), triglycerides (TG), low-density lipoprotein triglycerides (LDL-TG), very low-density lipoprotein triglyceride (VLDL-TG), high-density lipoprotein triglycerides (HDL-TG), and apo C-III. Atorvastatin 10 and 20 mg QD also resulted in significant increases in high-density lipoprotein cholesterol (HDL-C), apo AI, and LpAII:B:C:D:E. Due to its unique ability to normalize both cholesterol-rich and triglyceride-rich particles, atorvastatin is a promising candidate for monotherapy in a broad range of patients including those with varying degrees of hypercholesterolemia and hypertriglyceridemia.

Atorvastatin. A review of its pharmacology and therapeutic potential in the management of hyperlipidaemias

Atorvastatin is a synthetic HMG-CoA reductase inhibitor which lowers plasma cholesterol levels by inhibiting endogenous cholesterol synthesis. It also reduces triglyceride levels through an as yet unproven mechanism. Dose-dependent reductions in total cholesterol, low density lipoprotein (LDL)-cholesterol and triglyceride levels have been observed with atorvastatin in patients with hypercholesterolaemia and in patients with hypertriglyceridaemia. In large trials involving patients with hypercholesterolaemia, atorvastatin produced greater reductions in total cholesterol, LDL-cholesterol, apolipoprotein B and triglyceride levels than lovastatin, pravastatin and simvastatin. In patients with primary hypercholesterolaemia, the combination of atorvastatin and colestipol tended to produce larger reductions in LDL-cholesterol levels and smaller reductions in triglyceride levels than atorvastatin monotherapy. Although atorvastatin induced smaller reductions in triglyceride levels and more modest increases in high density lipoprotein (HDL)-cholesterol levels than either fenofibrate or nicotinic acid in patients with combined hyperlipidaemia, it produced larger reductions in total cholesterol and LDL-cholesterol. As with other HMG-CoA reductase inhibitors, the most frequently reported adverse events associated with atorvastatin are gastrointestinal effects. In comparative trials, atorvastatin had a similar adverse event profile to that of other HMG-CoA reductase inhibitors. Clinical data with atorvastatin are limited at present. However, with its ability to markedly reduce LDL-cholesterol levels, atorvastatin is likely to join other members of its class as a first-line agent for the treatment of patients with hypercholesterolaemia, if changes in lipid levels with atorvastatin convert to reductions in CHD mortality and morbidity. Atorvastatin may be particularly suitable for patients with heterozygous or homozygous familial hypercholesterolaemia because of the marked reductions in LDL-cholesterol experienced with the drug. Additionally, because of its triglyceride-lowering properties, atorvastatin appears to have the potential to become an appropriate treatment for patients with combined hyperlipidaemia or hypertriglyceridaemia.