Efficacy and safety of triple therapy (fluvastatin-bezafibrate-cholestyramine) for severe familial hypercholesterolemia

Fluvastatin for lowering lipids

BACKGROUND

Fluvastatin is thought to be the least potent statin on the market, however, the dose-related magnitude of effect of fluvastatin on blood lipids is not known.

OBJECTIVES

Primary objectiveTo quantify the effects of various doses of fluvastatin on blood total cholesterol, low-density lipoprotein (LDL cholesterol), high-density lipoprotein (HDL cholesterol), and triglycerides in participants with and without evidence of cardiovascular disease.Secondary objectivesTo quantify the variability of the effect of various doses of fluvastatin.To quantify withdrawals due to adverse effects (WDAEs) in randomised placebo-controlled trials.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to February 2017: the Cochrane Central Register of Controlled Trials (CENTRAL) (2017, Issue 1), MEDLINE (1946 to February Week 2 2017), MEDLINE In-Process, MEDLINE Epub Ahead of Print, Embase (1974 to February Week 2 2017), the World Health Organization International Clinical Trials Registry Platform, CDSR, DARE, Epistemonikos and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. No language restrictions were applied.

SELECTION CRITERIA

Randomised placebo-controlled and uncontrolled before and after trials evaluating the dose response of different fixed doses of fluvastatin on blood lipids over a duration of three to 12 weeks in participants of any age with and without evidence of cardiovascular disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included, and extracted data. We entered data from placebo-controlled and uncontrolled before and after trials into Review Manager 5 as continuous and generic inverse variance data, respectively. WDAEs information was collected from the placebo-controlled trials. We assessed all trials using the 'Risk of bias' tool under the categories of sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other potential biases.

MAIN RESULTS

One-hundred and forty-five trials (36 placebo controlled and 109 before and after) evaluated the dose-related efficacy of fluvastatin in 18,846 participants. The participants were of any age with and without evidence of cardiovascular disease, and fluvastatin effects were studied within a treatment period of three to 12 weeks. Log dose-response data over doses of 2.5 mg to 80 mg revealed strong linear dose-related effects on blood total cholesterol and LDL cholesterol and a weak linear dose-related effect on blood triglycerides. There was no dose-related effect of fluvastatin on blood HDL cholesterol. Fluvastatin 10 mg/day to 80 mg/day reduced LDL cholesterol by 15% to 33%, total cholesterol by 11% to 25% and triglycerides by 3% to 17.5%. For every two-fold dose increase there was a 6.0% (95% CI 5.4 to 6.6) decrease in blood LDL cholesterol, a 4.2% (95% CI 3.7 to 4.8) decrease in blood total cholesterol and a 4.2% (95% CI 2.0 to 6.3) decrease in blood triglycerides. The quality of evidence for these effects was judged to be high. When compared to atorvastatin and rosuvastatin, fluvastatin was about 12-fold less potent than atorvastatin and 46-fold less potent than rosuvastatin at reducing LDL cholesterol. Very low quality of evidence showed no difference in WDAEs between fluvastatin and placebo in 16 of 36 of these short-term trials (risk ratio 1.52 (95% CI 0.94 to 2.45).

AUTHORS' CONCLUSIONS

Fluvastatin lowers blood total cholesterol, LDL cholesterol and triglyceride in a dose-dependent linear fashion. Based on the effect on LDL cholesterol, fluvastatin is 12-fold less potent than atorvastatin and 46-fold less potent than rosuvastatin. This review did not provide a good estimate of the incidence of harms associated with fluvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 56% of the placebo-controlled trials.

The genetic landscape of Alzheimer disease: clinical implications and perspectives

The search for the genetic factors contributing to Alzheimer disease (AD) has evolved tremendously throughout the years. It started from the discovery of fully penetrant mutations in Amyloid precursor protein, Presenilin 1, and Presenilin 2 as a cause of autosomal dominant AD, the identification of the ɛ4 allele of Apolipoprotein E as a strong genetic risk factor for both early-onset and late-onset AD, and evolved to the more recent detection of at least 21 additional genetic risk loci for the genetically complex form of AD emerging from genome-wide association studies and massive parallel resequencing efforts. These advances in AD genetics are positioned in light of the current endeavor directing toward translational research and personalized treatment of AD. We discuss the current state of the art of AD genetics and address the implications and relevance of AD genetics in clinical diagnosis and risk prediction, distinguishing between monogenic and multifactorial AD. Furthermore, the potential and current limitations of molecular reclassification of AD to streamline clinical trials in drug development and biomarker studies are addressed.

Genet Med18 5, 421–430.

The evolution of preclinical Alzheimer's disease: implications for prevention trials

As the field begins to test the concept of a "preclinical" stage of neurodegenerative disease, when the pathophysiological process has begun in the brain, but clinical symptoms are not yet manifest, a number of intriguing questions have already arisen. In particular, in preclinical Alzheimer's disease (AD), the temporal relationship of amyloid markers to markers of neurodegeneration and their relative utility in the prediction of cognitive decline among clinically normal older individuals remains to be fully elucidated. Secondary prevention trials in AD have already begun in both genetic at-risk and amyloid at-risk cohorts, with several more trials in the planning stages, and should provide critical answers about whether intervention at this very early stage of disease can truly bend the curve of clinical progression. This review will highlight recent progress in cognitive, imaging, and biomarker outcomes in the field of preclinical AD, and the remaining gaps in knowledge.

Guidelines for the diagnosis and management of heterozygous familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a genetic disorder of lipoprotein metabolism characterized by very high plasma concentrations of low density lipoprotein cholesterol (LDLc), tendon xanthomas and increased risk of premature coronary heart disease (CHD). FH is a public health problem throughout the world. There are 10,000,000 people with FH worldwide, mainly heterozygotes, and approximately 85% of males and 50% of females with FH will suffer a coronary event before 65 years old if appropriate preventive efforts are not implemented. Early identification of persons with FH and their relatives, and the early start of treatment are essential issues in the prevention of premature cardiovascular disease (CVD) and death in this population. However, guidelines for the general population formally exclude FH from their diagnostic and treatment recommendations. These guidelines have been elaborated by a group of international experts with the intention to answer the main questions about heterozygous FH (heFH) subjects that physicians worldwide face in the diagnosis and management of these patients.

Benefits and risks of simvastatin in patients with familial hypercholesterolaemia

Familial hypercholesterolaemia is a frequent, inherited, monogenic disorder, associated with accelerated development of atherosclerotic disease leading to coronary artery disease. Life expectancy of patients with familial hypercholesterolaemia is reduced by 15-30 years unless they are adequately treated with lipid-lowering therapy. Given the chronic nature of this disease, the selection of a therapeutic approach should be strongly based on its long-term safety and tolerability. The introduction of HMG-CoA reductase inhibitors has revolutionised the treatment of familial hypercholesterolaemia. Simvastatin 40-80 mg/day effectively reduces serum low density lipoprotein (LDL)-cholesterol levels. Furthermore, simvastatin reduces triglycerides and mildly raises high density lipoprotein-cholesterol levels. In addition to the hypolipidaemic effect, other potentially important effects, such as improvement of endothelial function and reduction of LDL oxidation and vascular inflammation, have been associated with HMG-CoA reductase inhibitor therapy. Simvastatin has also been shown to abolish the progression, and even facilitate the regression, of existing human atherosclerotic lesions. The good safety and tolerability profile of simvastatin is clearly highlighted by the low rate of therapy discontinuation observed in several population-based clinical trials. The most common adverse events leading to the discontinuation of therapy are gastrointestinal upset and headache. Asymptomatic elevations in liver transaminase levels and myopathy are uncommon. The overwhelming clinical evidence regarding the long-term use of HMG-CoA reductase inhibitor therapy in patients with familial hypercholesterolaemia together with the long-term safety data (particularly relating to simvastatin) provide support for the use of this drug as a first-line agent when pharmacological treatment is indicated. Early intervention with simvastatin treatment can be successfully implemented with favourable economic benefits.

Combination lipid-lowering therapy with statins: safety issues in the postcerivastatin era

Combination lipid-altering regimens represent an emerging clinical paradigm to meet increasingly stringent consensus lipoprotein targets for coronary prevention. This practice, together with escalating prevalences of coronary artery disease in certain ageing (western industrial) populations, polypharmacy in the elderly and the recent voluntary market withdrawal of cerivastatin, warrants a re-examination of the safety profiles of 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase inhibitors (i.e., statins). These agents are exceedingly well-tolerated in the vast majority of patients, very infrequently precipitating musculoskeletal symptoms and/or signs. Statins vary in their pharmacological profiles, leading to distinct levels of systemic exposure and capacities to penetrate skeletal myocytes. Pharmacokinetic interactions with certain agents increase the likelihood of statin-induced myopathy and, in exceedingly rare instances, potentially fatal rhabdomyolysis with myoglobinuria and renal failure. As with other medical decisions, the anticipated benefits of long-term statin therapy, with or without other lipid-altering agents, need to be weighed against the prospects of clinically significant drug interactions. In clinical trials and postmarketing surveillance, the two statins that are not metabolised by the cytochrome P450 3A4 system (fluvastatin and pravastatin) have exhibited very low propensities to elicit myopathy when combined with other agents. These agents should be considered initially when contemplating combination lipid-lowering regimens for coronary prevention.

Familial hypercholesterolemia--improving treatment and meeting guidelines

Familial hypercholesterolemia (FH) is a common, inherited disorder that affects around one in 500 individuals in the heterozygous form. By the year 2001, more people in the US had FH than were infected by the human immunodeficiency virus. The disease is caused by mutations within the low-density lipoprotein (LDL) receptor gene. FH is associated with elevated plasma LDL-cholesterol (LDL-C) levels, xanthomatosis, early onset of atherosclerosis and premature cardiac death. Patients with heterozygous FH commonly have plasma LDL-C levels that are two-fold higher than normal, while homozygotes have four- to five-fold elevations in plasma LDL-C. Although FH patients have a high risk of developing premature coronary heart disease (CHD), they remain underdiagnosed and undertreated. Early detection of FH is critical to prolonging the life of these patients. Once identified, patients with heterozygous FH can be placed on a diet and drug management program. As the most efficacious and well-tolerated agents, hydroxy methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are usually the drugs of first choice; bile acid sequestrants, niacin, and occasionally fibrates may be used as supplemental agents. Statins may also provide a realistic option for the treatment of some FH homozygotes with genes that produce partially functional LDL receptors. However, a number of patients are still failing to reach treatment guidelines even with the most effective of the currently available statins. The development of new more efficacious statins or the use of new combination therapies such as statins with the cholesterol absorption inhibitor, ezetimibe may help to reduce the current problem of undertreatment in FH patients.

Peroxisome proliferator-activated receptor agonists, hyperlipidaemia, and atherosclerosis

Dyslipidaemia is a major risk factor in the development of atherosclerosis, and lipid lowering is achieved clinically using fibrate drugs and statins. Fibrate drugs are ligands for the fatty acid receptor peroxisome proliferator-activated receptor (PPAR)alpha, and the lipid-lowering effects of this class of drugs are mediated by the control of lipid metabolism, as directed by PPARalpha. PPARalpha ligands also mediate potentially protective changes in the expression of several proteins that are not involved in lipid metabolism, but are implicated in the pathogenesis of heart disease. Clinical studies with bezafibrate and gemfibrozil support the hypothesis that these drugs may have a significant protective effect against cardiovascular disease. The thiazolidinedione group of insulin-sensitising drugs are PPARgamma ligands, and these have beneficial effects on serum lipids in diabetic patients and have also been shown to inhibit the progression of atherosclerosis in animal models. However, their efficacy in the prevention of cardiovascular-associated mortality has yet to be determined. Recent studies have found that PPARdelta is also a regulator of serum lipids. However, there are currently no drugs in clinical use that selectively activate this receptor. It is clear that all three forms of PPARs have mechanistically different modes of lipid lowering and that drugs currently available have not been optimised on the basis of PPAR biology. A new generation of rationally designed PPAR ligands may provide substantially improved drugs for the prevention of cardiovascular disease.

Familial Hypercholesterolemia

Heterozygous familial hypercholesterolemia is a common, severe form of elevated plasma, low-density lipoprotein (LDL) cholesterol. Familial hypercholesterolemia is under-recognized and under-treated despite well-known benefits from available lipid-lowering medications. To help address these problems, the humanitarian MEDPED (Make Early Diagnoses, Prevent Early Deaths) organization was developed as a means to find and help persons with familial hypercholesterolemia all over the world. Although some patients with familial hypercholesterolemia can be treated adequately with a statin alone, many require aggressive treatment with a combination of drugs, including a statin, bile acid sequestrant, and niacin to reach LDL goals. Such treatment has resulted in regression of angiographically monitored coronary lesions in patients with familial hypercholesterolemia.

Combination lipid-altering therapy: an emerging treatment paradigm for the 21st century

For the care of an expanding segment of the US population with multiple coronary risk factors, combination lipid-altering therapy is emerging as a treatment imperative. The most recent National Cholesterol Education Program's consensus guidelines emphasize long-term global coronary heart disease (CHD) risk status, designate patients with CHD risk equivalents (eg, diabetes, peripheral arterial disease, 20% or more 10-year absolute CHD risk) for aggressive lipid-altering therapy, and deem the metabolic syndrome (eg, obesity, insulin resistance, hypertension, elevated triglycerides, low levels of high-density lipoprotein cholesterol, small dense low-density lipoprotein particles) as a secondary target for intervention. With the advancing age of the US population and the high prevalence of diabetes, the metabolic syndrome, and CHD, increasing numbers of patients will require a more balanced metabolic attack attainable only through combination lipid-altering regimens. Many of these patients, as well as persons at heightened risk for cardiovascular disease because of a range of heritable conditions (eg, familial hypercholesterolemia, familial combined hyperlipidemia), will undoubtedly require binary or ternary regimens involving statins in concert with niacin, fibric-acid derivatives, or bile acid resins. Such approaches enable the clinician to exploit the complementary effects of these agents, allowing them to be administered at low, optimally tolerable doses that are consistent with superior efficacy and a lower risk of adverse events as compared with escalating doses of monotherapy.

Statin-fibrate combination therapy

BACKGROUND

Precautionary warnings for severe myopathy and rhabdomyolysis from the coadministration of statins and fibrates have been well publicized. However, a recent cerivastatin labeling change made the combined use with fibric acid derivatives a contraindication. Practical recommendations for clinicians who care for patients with refractory mixed hyperlipidemia are needed.

OBJECTIVE

To provide recommendations for clinicians in the treatment of refractory mixed hyperlipidemia.

DATA SOURCES

A comprehensive MEDLINE (1966-July 2000) and bibliographic search was performed.

DATA SYNTHESIS

Thirty-six published clinical trials and 29 case reports involving combination therapy with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and fibric acid derivatives regarding the occurrence of rhabdomyolysis or myopathy were reviewed. The literature review demonstrated that combination therapy with a statin and fibrate increases the risk of muscle damage, with an incidence of 0.12%. Risk factors that predispose patients to myopathy caused by combination statin-fibrate therapy include increased age, female gender, renal or liver disease, diabetes, hypothyroidism, debilitated status, surgery, trauma, excessive alcohol intake, and heavy exercise.

CONCLUSIONS

Combination therapy with a statin and fibrate offers significant therapeutic advantage for the treatment of severe or refractory mixed hyperlipidemia. Although such a combination does increase the risk of myopathy, with an incidence of approximately 0.12%, this small risk of myopathy rarely outweighs the established morbidity and mortality benefits of achieving lipid goals. Nevertheless, a higher incidence of myopathy has been reported with statin monotherapy. When monotherapy with a statin fails to control mixed hyperlipidemia, combination therapy may be considered. Niacin may be added before a fibrate is considered, as it appears to have less risk of myopathy. Statin-fibrate combination therapy must be undertaken cautiously and only after careful risk-benefit analysis. Patient counseling on the risks and warning signs of myopathy is extremely important.

Role of fibrates in the management of hypertriglyceridemia

Elevated plasma triglyceride levels are increasingly recognized as a risk factor for cardiovascular disease. Fibric acid derivatives (fibrates) substantially decrease triglyceride levels and have been demonstrated to decrease clinical cardiovascular events in some trials. Ongoing research will elucidate the molecular mechanisms by which fibrates modify lipoprotein metabolism, clarify their use in combination with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins), and determine their role in the prevention of cardiovascular events.

Pharmacokinetics of the combination of fluvastatin and gemfibrozil

High-risk patients with dyslipidemias resistant to diet and single-agent pharmacotherapy may require combination therapy to achieve target levels of low density lipoprotein, triglycerides, and high density lipoprotein. Combinations of fibrates and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors are effective, but because of safety concerns related to myopathy and rhabdomyolysis, it is important to consider the possibility of pharmacokinetic interactions when such combinations are used. In this study, the area under the curve, maximum plasma concentration, and time to maximum concentration for fluvastatin and gemfibrozil are compared, when used alone and in combination, in patients with hyperlipidemia and either coronary or carotid atherosclerosis, or a family history of coronary artery disease. A total of 17 patients were studied in a random sequence, open-label, crossover study of fluvastatin at 20 mg twice daily, gemfibrozil at 600 mg twice daily, and the combination of the 2 drugs. No significant difference was observed in area under the curve, maximum plasma concentration, and time to maximum concentration when comparing the combination with each drug alone. These pharmacokinetic data add support to the clinical observations that the combination of fluvastatin and gemfibrozil is both effective and safe.