Clinically relevant differences between the statins: implications for therapeutic selection

Simvastatin for cognitive deficits and behavioural problems in patients with neurofibromatosis type 1 (NF1-SIMCODA): a randomised, placebo-controlled trial

BACKGROUND

Neurofibromatosis type 1 is a common genetic disorder characterised by neurocutaneous manifestations and cognitive and behavioural problems. Statins were shown to reduce analogous learning deficits in a mouse model of the disease, but a short-term trial in humans was inconclusive. We aimed to assess the use of simvastatin for the improvement of cognitive and behavioural deficits in children with neurofibromatosis type 1 for 12 months.

METHODS

In this randomised, double-masked, placebo-controlled trial, we recruited children with genetically confirmed neurofibromatosis type 1 aged 8-16 years from two national referral centres in the Netherlands and Belgium. Those with symptomatic CNS abnormalities or on neurotropic medication, including stimulants, were excluded. Eligible patients were randomly assigned (1:1) via a computer-generated, permuted-block list to simvastatin (10 mg per day in month 1, 20 mg per day in month 2, and 20-40 mg per day in months 3-12) or placebo for 12 months. Investigators, participants, and parents were masked to treatment assignment. Primary outcome measures were full-scale intelligence (Wechsler intelligence scale for children), attention problems (child behaviour checklist, parent-rated [CBCL]), and internalising behavioural problems (CBCL). We did intention-to-treat analyses (of all patients who had outcome data) using linear regression of the 12 month outcome scores, adjusted for baseline performance. This trial is registered with the Netherlands Trial Register, number NTR2150.

FINDINGS

We randomly assigned 84 children to a treatment group (43 to simvastatin, 41 to placebo) between March 9, 2010, and March 6, 2012. We did not assess outcomes in two patients in the placebo group because they needed additional drug therapy. Simvastatin for 12 months had no effect on full-scale intelligence (treatment effect compared with placebo -1·3 IQ points [95% CI -3·8 to 1·3]; p=0·33), attention problems (-1·6 T-score points [-4·3 to 1·0]; p=0·23), and internalising behavioural problems (-0·1 T-score points [-3·3 to 3·1]; p=0·96). 38 (88%) of 43 patients on simvastatin and 39 (95%) of 41 patients on placebo reported adverse events, which were serious in two and four patients, respectively.

INTERPRETATION

12 month simvastatin treatment did not ameliorate cognitive deficits or behavioural problems in children with neurofibromatosis type 1. The use of 20-40 mg simvastatin per day for cognitive enhancement in children with neurofibromatosis type 1 is not recommended.

FUNDING

The Netherlands Organization for Health Research and Development (ZonMw), Research Foundation Flanders (FWO-Vlaanderen), Marguerite-Marie Delacroix Foundation, and the Dutch Neurofibromatosis Association (NFVN).

Rhabdomyolysis after Concomitant Use of Simvastatin and Voriconazole in an Allogeneic Stem Cell Transplant Patient

Objective:

To report a case of rhabdomyolysis after concomitant use of simvastatin and voriconazole.

Case Summary:

A 65-year-old white male, weight 66 kg, 79 months post allogeneic stem cell transplant for chronic lymphocytic leukemia, was on a stable medication regimen that included voriconazole. He was hospitalized with weakness and elevated creatine kinase a few weeks after initiation of simvastatin for treatment of hyperlipidemia. His symptoms resolved and creatine kinase level returned to within the normal range after fluid administration and discontinuation of simvastatin.

Discussion:

The use of statins has become a standard in the treatment and prevention of atherosclerotic disease. Most statins are metabolized via the cytochrome P450 enzyme system. For simvastatin, metabolism occurs specifically via the CYP3A4 isoenzyme. Drugs known to inhibit this isoenzyme, such as voriconazole, can increase the risk for toxicities, including rhabdomyolysis, when used concomitantly with simvastatin. This case represents a probable drug-drug interaction, based on the Horn Drug Interaction Probability Scale.

Conclusions:

Due to the broad use of statins for the treatment and prevention of atherosclerotic disease, as well as the need for azole antifungals in the stem cell transplant population, interactions between these agents are becoming an increasing possibility. Care should be taken to minimize these interactions and, when feasible, a change to an alternative agent may be warranted to avoid adverse effects.

Targeting the host or the virus: current and novel concepts for antiviral approaches against influenza virus infection

Influenza epidemics and pandemics are constant threats to human health. The application of antiviral drugs provides an immediate and direct control of influenza virus infection. At present, the major strategy for managing patients with influenza is through targeting conserved viral proteins critical for viral replication. Two classes of conventional antiviral drugs, the M2 ion channel blockers and the neuraminidase inhibitors, are frequently used. In recent years, increasing levels of resistance to both drug classes has become a major public health concern, highlighting the urgent need for the development of alternative treatments. Novel classes of antiviral compounds or biomolecules targeting viral replication mechanism are under development, using approaches including high-throughput small-molecule screening platforms and structure-based designs. In response to influenza virus infection, host cellular mechanisms are triggered to defend against the invaders. At the same time, viruses as obligate intracellular pathogens have evolved to exploit cellular responses in support of their efficient replication, including antagonizing the host type I interferon response as well as activation of specific cellular pathways at different stages of the replication cycle. Numerous studies have highlighted the possibility of targeting virus-host interactions and host cellular mechanisms to develop new treatment regimens. This review aims to give an overview of current and novel concepts targeting the virus and the host for managing influenza.

Association of pre-transplant statin use with delayed graft function in kidney transplant recipients

Background

Administration of HMG-CoA reductase inhibitors (statins), prior to ischemia or prior to reperfusion has been shown to decrease ischemia-reperfusion renal injury in animal studies. It is unknown whether this protective effect is applicable to renal transplantation in humans. The aim of this study was to determine the relationship between prior statin use in renal transplant recipients and the subsequent risk of delayed graft function.

Methods

All patients who underwent deceased or living donor renal transplantation at the Princess Alexandra Hospital between 1 July 2008 and 1 August 2010 were included in this retrospective, observational cohort study. Graft function was classified as immediate graft function (IGF), dialysis-requiring (D-DGF) and non-dialysis-requiring (ND-DGF) delayed graft function. The independent predictors of graft function were evaluated by multivariable logistic regression, adjusting for donor characteristics, recipient characteristics, HLA mismatch and ischaemic times.

Results

Overall, of the 266 renal transplant recipients, 21% exhibited D-DGF, 39% had ND-DGF and 40% had IGF. Statin use prior to renal transplantation was not significantly associated with the risk of D-DGF (adjusted odds ratio [OR] 1.05, 95% CI 0.96 – 1.15, P = 0.28). This finding was not altered when D-DGF and ND-DGF were pooled together (OR 0.98; 95% CI 0.89-1.06, p = 0.56).

Conclusions

The present study did not show a significant, independent association between prior statin use in kidney transplant recipients and the occurrence of delayed graft function.

Polymorphisms in the mitochondrial ribosome recycling factor EF-G2mt/MEF2 compromise cell respiratory function and increase atorvastatin toxicity

Mitochondrial translation, essential for synthesis of the electron transport chain complexes in the mitochondria, is governed by nuclear encoded genes. Polymorphisms within these genes are increasingly being implicated in disease and may also trigger adverse drug reactions. Statins, a class of HMG-CoA reductase inhibitors used to treat hypercholesterolemia, are among the most widely prescribed drugs in the world. However, a significant proportion of users suffer side effects of varying severity that commonly affect skeletal muscle. The mitochondria are one of the molecular targets of statins, and these drugs have been known to uncover otherwise silent mitochondrial mutations. Based on yeast genetic studies, we identify the mitochondrial translation factor MEF2 as a mediator of atorvastatin toxicity. The human ortholog of MEF2 is the Elongation Factor Gene (EF-G) 2, which has previously been shown to play a specific role in mitochondrial ribosome recycling. Using small interfering RNA (siRNA) silencing of expression in human cell lines, we demonstrate that the EF-G2mt gene is required for cell growth on galactose medium, signifying an essential role for this gene in aerobic respiration. Furthermore, EF-G2mt silenced cell lines have increased susceptibility to cell death in the presence of atorvastatin. Using yeast as a model, conserved amino acid variants, which arise from non-synonymous single nucleotide polymorphisms (SNPs) in the EF-G2mt gene, were generated in the yeast MEF2 gene. Although these mutations do not produce an obvious growth phenotype, three mutations reveal an atorvastatin-sensitive phenotype and further analysis uncovers a decreased respiratory capacity. These findings constitute the first reported phenotype associated with SNPs in the EF-G2mt gene and implicate the human EF-G2mt gene as a pharmacogenetic candidate gene for statin toxicity in humans.

The mitochondria are responsible for producing the cell's energy. Energy production is the result of carefully orchestrated interactions between proteins encoded by the mitochondrial DNA and by nuclear DNA. Sequence variations in genes encoding these proteins have been shown to cause disease and adverse drug reactions in patients. The cholesterol-lowering drugs statins are one class of drugs that interfere with mitochondrial function. Statins are one of the most prescribed drugs in the western world, but many users suffer side effects, commonly muscle pain. In severe cases this can lead to muscle breakdown and liver failure. In this study, we discover that disruption of a mitochondrial translation gene, EF-G2mt, impedes respiration and increases cell death when exposed to statin. Using the simple unicellular organism yeast as a model, the activity of naturally occurring human EF-G2mt variants is tested. Three of these variants render yeast cells more sensitive to statin. Patients who possess these EF-G2mt variations may be more susceptible to statin side effects. Importantly, the test for statin sensitivity also led to the discovery of mutants that have a reduced energy production capacity. The decreased ability to produce energy is linked to a number of diseases, including myopathies and liver failure.

Influence of atorvastatin on the pharmacodynamic and pharmacokinetic activity of repaglinide in rats and rabbits

Dyslipidemia is common in patients with type 2 diabetes. Statins are used as the first choice in treatment of diabetic dyslipidemia. Atorvastatin represents a first-line treatment option, alongside other hydroxyl methylglutaryl coenzyme A reductase inhibitors. Repaglinide is a short-acting, oral, insulin secretagogue that is used in the treatment of type 2 diabetes mellitus. Both the category of drugs undergo extensive metabolism with cytochrome enzyme system. This may lead to drug-drug interaction problems with altered repaglinide activity which is cautious. Repaglinide/atorvastatin/atorvastatin + repaglinide were administered orally to normal, diabetic rats, and to normal rabbits. Blood samples were collected at different time intervals and were analyzed for blood glucose by GOD-POD method using commercial glucose kits and repaglinide estimation in plasma by HPLC method. Diabetes was induced by alloxan 100 mg/kg body weight administered by I.P route. In the presence of atorvastatin, repaglinide activity was increased and maintained for longer period in diabetic rats compared with repaglinide matching control. The present study concludes co-administration of atorvastatin was found to improve repaglinide responses significantly in diabetic rats and improved glucose metabolism of atorvastatin played an important role and increased repaglinide levels by competitive CYP 3A4 enzyme inhibition by atorvastatin could be added advantage for anti hyperglycemic activity.

Fluvastatin modulates renal water reabsorption in vivo through increased AQP2 availability at the apical plasma membrane of collecting duct cells

X-linked nephrogenic diabetes insipidus (XNDI), a severe pathological condition characterized by greatly impaired urine-concentrating ability of the kidney, is caused by inactivating mutations in the V2 vasopressin receptor (V2R) gene. The lack of functional V2Rs prevents vasopressin-induced shuttling of aquaporin-2 (AQP2) water channels to the apical plasma membrane of kidney collecting duct principal cells, thus promoting water reabsorption from urine to the interstitium. At present, no specific pharmacological therapy exists for the treatment of XNDI. We have previously reported that the cholesterol-lowering drug lovastatin increases AQP2 membrane expression in renal cells in vitro. Here we report the novel finding that fluvastatin, another member of the statins family, greatly increases kidney water reabsorption in vivo in mice in a vasopressin-independent fashion. Consistent with this observation, fluvastatin is able to increase AQP2 membrane expression in the collecting duct of treated mice. Additional in vivo and in vitro experiments indicate that these effects of fluvastatin are most likely caused by fluvastatin-dependent changes in the prenylation status of key proteins regulating AQP2 trafficking in collecting duct cells. We identified members of the Rho and Rab families of proteins as possible candidates whose reduced prenylation might result in the accumulation of AQP2 at the plasma membrane. In conclusion, these results strongly suggest that fluvastatin, or other drugs of the statin family, may prove useful in the therapy of XNDI.

Statin discontinuation and risk of acute myocardial infarction in patients with rheumatoid arthritis: a population-based cohort study

OBJECTIVES

Screening for cardiovascular risk factors and treating hyperlipidaemia with statins are recommended to reduce the increased cardiovascular risk in individuals with rheumatoid arthritis (RA). However, poor compliance with statins may limit their therapeutic benefit. Our objective was to evaluate the impact of statin discontinuation on risk of acute myocardial infarction (AMI) among RA patients.

METHODS

The authors conducted a population-based cohort study of RA patients with incident statin use followed from May 1996 to March 2006 using administrative health data. Primary exposure was statin discontinuation for ≥ 3 months at any time during therapy course. The authors used Cox's proportional hazards models and modelled statin discontinuation as a time-dependent variable, while adjusting for age, sex, comorbidities, use of other medications influencing cardiac risk, and proxy indicators of RA severity.

RESULTS

During 15 669 person-years of follow-up in 4102 incident-statin users with RA, the authors identified 264 AMI events. Statin discontinuation was associated with 67% increased risk of AMI (adjusted HR 1.67; 95% CI 1.24 to 2.25). There was a 2% increase in risk of AMI with each 1-month increase in the duration of discontinuation (adjusted HR 1.02; 95% CI 1.01 to 1.03). These associations were not modified by timing of first statin prescription, prior AMI status, sex and age (p values for interactions >0.17).

CONCLUSIONS

These population-based data indicate that RA patients who discontinue statins have increased risk of AMI. Findings emphasise the need to raise awareness, among health professionals and people with RA, of the importance of compliance with statin therapy in RA.

Safety of fluvastatin in patients undergoing high-risk non-cardiac surgery

IMPORTANCE OF THE FIELD

In patients undergoing vascular surgery there is a high incidence of adverse cardiac events, due to sudden coronary plaque rupture. The non-lipid lowering or pleiotropic effects of statins can help reduce adverse cardiovascular events associated with vascular surgery.

AREAS COVERED IN THIS REVIEW

The evidence for perioperative use of fluvastatin, as well as other statins, in high-risk surgery patients is summarized in this review. Data on pharmacokinetics and metabolism is presented, together with considerations on possible drug interactions in the perioperative period.

WHAT THE READER WILL GAIN

The reader will gain a comprehensive understanding of the existing safety and efficacy data for fluvastatin and other statins in the perioperative period. The practical considerations of perioperative fluvastatin therapy will be presented, including potential side-effects and management of the early non-oral phase immediately post surgery. Finally, advice on when to initiate therapy and safety recommendations are offered.

TAKE HOME MESSAGE

In patients scheduled for high-risk vascular surgery, fluvastatin improves postoperative outcome, reducing the incidence of myocardial damage by approximately 50% in the first 30 days following vascular surgery. In comparison with placebo, fluvastatin was not associated with a rise in liver enzymes or creatine kinase levels. To bridge the non-oral phase, an extended-release formula is recommended.

Prescription of lipophilic statins to Alzheimer's disease patients: some controversies to consider

Alzheimer's disease (AD) is the most common disorder causing cognitive decline in old age. It is a progressive and irreversible neuropathology with a diagnosis often missed or delayed. Cholesterol represents an important determinant of the physical state of biological membranes and in AD brains, specific changes in its membrane-ordering and Raft-organizing effects take place. A recent publication shows downregulation of Seladin-1 (selective Alzheimer's disease indicator, also called DHCR24), which catalyzes the last step of cholesterol biosynthesis in affected neurons in AD. Postmortem analysis of AD brains revealed a loss in membrane cholesterol content and this finding makes the therapeutical use of statins (especially the lipophilic ones) quite a lot controversial. Some clinical studies suggest that risk of Alzheimer's disease is substantially reduced in users of statins; however, because these studies are not randomized trials, they provide insufficient evidence to recommend statin family therapy.

Disorders of lipid metabolism and chronic kidney disease in the elderly

The growing population of elderly with chronic kidney disease (CKD) is at greater risk for cardiovascular disease given an independent risk of CKD, as well as from added dyslipidemia of aging and renal dysfunction. Changes in lipid metabolism with more isodense and high-dense, triglyceride-rich particles, low high-density lipoprotein cholesterol, and increased triglyceride levels occur with CKD and aging, which are noted to have significant atherogenic potential. In addition, lipid abnormalities may lead to the progression of CKD. Cardiovascular mortality in the end-stage renal disease population is more than 10 times higher than the general population. Treatment of dyslipidemia in the general population suggests important benefits both in reducing cardiovascular risk and in the prevention of cardiovascular disease. Secondary analyses of elderly subgroups of various large prospective studies with statins suggest treatment benefit with statin use in the elderly. Similarly limited data from secondary analyses of CKD subgroups of larger prospective trials using statins also suggest a possible benefit in cardiovascular outcomes and the progression of kidney disease. However, randomized trials have yet to confirm similar benefits and targets of treatment for dyslipidemia in the elderly with CKD and end-stage renal disease. Treatment in the elderly with CKD should be individualized and outweigh risks of side effects and drug-drug interactions. There is a need for further specific investigation of dyslipidemia of CKD in the aging population in relation to renal disease progression and cardiovascular outcome.

Do statins reduce hepatitis C RNA titers during routine clinical use?

AIM: To compare hepatitis C virus (HCV) titers in patients with chronic hepatitis C with and without exposure to 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins).

METHODS: Medical records were reviewed for 6463 patients with documented HCV infection at a single center between March 2004 and September 2006. Patients with confirmed viremia and meeting inclusion criteria were assigned to one of three groups: Group A (n = 50), dyslipidemic patients with statin usage during HCV RNA polymerase chain reaction (PCR) determination; Group B (n = 49), dyslipidemic patients with prior or future statin usage but not at the time of HCV RNA PCR determination; and Group C (n = 102), patients without statin usage during the study period. The primary analysis explored the effect of statin therapy on HCV viremia. Secondary analyses assessed class effect, dose response, and effect of other lipid-lowering therapies on HCV viral titers.

RESULTS: Median HCV RNA titers did not significantly differ among the three groups (Group A: 4 550 000 IU/mL, Group B: 2 850 000 IU/mL, Group C: 3 055 000 IU/mL). For those subjects with longitudinal assessment of HCV viremia prior to and while on statins, there were no significant differences between pre- and post-HCV viral titers. Additionally, no differences in HCV titers were observed at any dose level of the most prescribed statin, simvastatin. However, hypertriglyceridemia independently correlated with HCV titers, and niacin exposure was associated with significantly lower viral titers (P < 0.05).

CONCLUSION: There was no apparent effect of statins on HCV viral replication in this analysis. Further investigation is warranted to explore the possible antiviral properties of triglyceride-lowering agents and their potential role as adjuncts to standard HCV therapy.

Chronic treatment with pravastatin prevents early cardiovascular changes in spontaneously hypertensive rats

BACKGROUND AND PURPOSE

This study investigates the effect of pravastatin on blood pressure, cardiovascular remodelling and impaired endothelial function induced as early signs of cardiovascular disease in young spontaneously hypertensive rats (SHR).

EXPERIMENTAL APPROACH

Eight-week-old SHR were treated for 4 weeks with pravastatin (20 mg kg(-1) day(-1)). Systolic blood pressure was measured periodically during the study using the tail-cuff method. At the end of the study, the left ventricular weight /body weight ratio was used as an index of left ventricular hypertrophy (LVH). Vascular function, superoxide (O(2)(-*)) production and structure were studied in aortic rings. Lipid peroxidation was measured in plasma (thiobarbituric acid reactive substances assay).

KEY RESULTS

Systolic blood pressure was lower in treated SHR than in control SHR, at the end of the study (171 +/- 1 vs. 159 +/- 2 mmHg, P < 0.05), and LVH was significantly reduced by pravastatin (2.7 +/- 0.02 vs. 2.5 +/- 0.01 mg g(-1), P < 0.05). Vascular responses to sodium nitroprusside and phenylephrine were similar in both groups; nevertheless, the relaxation response to acetylcholine was higher in the treated rats (45.6 +/- 2.6 vs. 58.1 +/- 3.2 %, P < 0.05). Vascular O(2)(-*) and plasma thiobarbituric acid reactive substances were reduced by pravastatin treatment, and urinary nitrites was elevated. Finally aortic wall became thinner after pravastatin treatment.

CONCLUSIONS AND IMPLICATIONS

Chronic treatment with pravastatin attenuated the increase of systolic blood pressure in SHR, prevented early LVH and improved vascular structure and function. These effects were accompanied by decreased measures of oxidative stress and improvements in NO production.

Statin-induced liver injury involves cross-talk between cholesterol and selenoprotein biosynthetic pathways

Statins have become the mainstay of hypercholesterolemia treatment. Despite a seemingly clear rationale behind their use, the inhibition of HMG-CoA reductase, these compounds have been shown to elicit a variety of unanticipated and elusive effects and side effects in vivo. Among the most frequently noted side effects of statin treatment are elevations in liver enzymes. Here, we report our finding that atorvastatin, cerivastatin, and lovastatin at clinically common concentrations induce a selective, differential loss of selenoprotein expression in cultured human HepG2 hepatocytes. The primarily affected selenoprotein was glutathione peroxidase (GPx), whose biosynthesis, steady-state expression level, and catalytic activity were significantly reduced with 10 to 100 nM concentrations of the different compounds. Messenger RNA levels of GPx1 and GPx4 were unaffected by statin treatment, pointing at a post-transcriptional mechanism of selenoprotein suppression. Although statins at selenoprotein-modulatory doses were not cytotoxic by themselves, they induced a significantly increased sensitivity of the cells to peroxides, an effect that was largely reversible by supraphysiological concentrations of selenite. We conclude that statins inhibit the expression of inducible selenoproteins by preventing the mevalonate-dependent maturation of the single human selenocysteine-tRNA and may thereby evoke an increased vulnerability of the liver to secondary toxins. Selenoprotein modulation might constitute an important mechanism of statins to bring forth their clinical effects.

Differences in antitumor effects of various statins on human pancreatic cancer

Statins are widely used for the treatment of hypercholesterolemia. However, their inhibitory action on HMG-CoA reductase also results in the depletion of intermediate biosynthetic products, which importantly contribute to cell proliferation. The aim of the present study was to compare the effects of the individual commercially available statins on experimental pancreatic cancer. The in vitro effects of individual statins (pravastatin, atorvastatin, simvastatin, lovastatin, cerivastatin, rosuvastatin and fluvastatin) on the viability of human pancreatic cancer were evaluated in CAPAN-2, BxPc-3 and MiaPaCa-2 cell lines. The in vivo experiments were performed on nude mice xenotransplanted with CAPAN-2 cells. The mice received oral treatments either with a placebo, or with the statins mentioned earlier in a daily dose corresponding to a hypocholesterolemic dose in humans. The effect of these statins on the intracellular Ras protein, trafficking in MiaPaCa-2 transfected cells, was also investigated. Substantial differences in the tumor-suppressive effects of all statins were detected in both in vitro and in vivo experiments. While simvastatin exerted the highest tumor-suppressive effects in vitro, rosuvastatin (p = 0.002), cerivastatin (p = 0.002) and fluvastatin (p = 0.009) were the most potent compounds in an animal model. All statins (except pravastatin) inhibited intracellular Ras protein translocation. In summary, substantial tumor-suppressive effects of various statins on the progression of experimental pancreatic adenocarcinoma were demonstrated, with marked differences among individual statins. These results support greatly the potential of statins for the chemoadjuvant treatment of pancreatic cancer.

Effects of statins on renal function

Patients with chronic kidney disease (CKD) are much more likely to die of cardiovascular disease than end-stage renal disease. Dyslipidemia is highly prevalent in patients with CKD and may contribute to the elevated cardiovascular risk as well as CKD progression. Statins are lipid-lowering drugs that appear to protect the kidneys via cholesterol reduction as well as noncholesterol-mediated mechanisms. Subgroup analyses of major clinical studies and meta-analyses of smaller trials indicate that statin therapy slows the decline of the glomerular filtration rate. Additionally, statins appear to reduce proteinuria in patients with CKD. Statins are well recognized to reduce cardiovascular morbidity and mortality in patients with and without documented cardiovascular disease and in certain high-risk populations, such as persons with diabetes mellitus. However, conclusive evidence for improved cardiovascular outcomes with statin therapy for CKD is not yet available. Several ongoing studies are evaluating the effect of statins on cardiovascular end points in patients with CKD and may provide data needed to support adjunctive use of these agents in this high-risk population.

Effect of HMGCoA reductase inhibitors on cytochrome P450 expression in endothelial cell line

Endothelial cells and smooth muscle cells are the major cells that constitute blood vessels, and endothelial cells line the lumen of blood vessels. These 2 types of cells also play an integral role in the regional specialization of vascular structure. On the basis of these observations, we designed our study to investigate the effect of various statins on CYP expression in endothelial cells. 3-hydroxymethyl coenzyme A reductase inhibitors play an important role in vascular function. The majority of the statins available on the market show extensive metabolism by cytochrome P450 (CYP) enzymes. Both cell types are involved in the bioconversion of arachidonic acid into vasoactive compounds. The aim of this study was to demonstrate the effect of statins on cytochrome P450 expression in endothelial cells. Our results show that endothelial cells expressed both CYPs involved in epoxyeicosatrienoic acids (EETs) and hydroxyeicosatetraenoic acids (HETEs) production and the nuclear receptor implicated in cytochrome P450 regulation. Treatment of endothelial cells with lovastatin increased CYP2C9 expression. After 96 hours of treatment, fluvastatin and lovastatin clearly increased CYP2C9 protein level. CAR but not PXR was expressed in endothelial cells, indicating that the upregulating effect of statins on CYP2C9 in endothelial cells could be mediated through CAR only due to the lack of expression of PXR in these cells.

Effect of intensive lipid lowering with atorvastatin on renal function in patients with coronary heart disease: the Treating to New Targets (TNT) study

BACKGROUND AND OBJECTIVES

Data suggest that atorvastatin may be nephroprotective. This subanalysis of the Treating to New Targets study investigated how intensive lipid lowering with 80 mg of atorvastatin affects renal function when compared with 10 mg in patients with coronary heart disease.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 10,001 patients with coronary heart disease and LDL cholesterol levels of <130 mg/dl were randomly assigned to double-blind therapy with 10 or 80 mg/d atorvastatin. Estimated GFR using the Modification of Diet in Renal Disease equation was compared at baseline and at the end of follow-up in 9656 participants with complete renal data.

RESULTS

Mean estimated GFR at baseline was 65.6 +/- 11.4 ml/min per 1.73 m2 in the 10-mg group and 65.0 +/- 11.2 ml/min per 1.73 m2 in the 80-mg group. At the end of follow-up (median time to final creatinine measurement 59.5 months), mean change in estimated GFR showed an increase of 3.5 +/- 0.14 ml/min per 1.73 m2 with 10 mg and 5.2 +/- 0.14 ml/min per 1.73 m2 with 80 mg (P < 0.0001 for treatment difference). In the 80-mg arm, estimated GFR improved to > or = 60 ml/min per 1.73 m2 in significantly more patients and declined to < 60 ml/min per 1.73 m2 in significantly fewer patients than in the 10-mg arm.

CONCLUSIONS

The expected 5-yr decline in renal function was not observed. Estimated GFR improved in both treatment groups but was significantly greater with 80 mg than with 10 mg, suggesting this benefit may be dosage related.

Chromatography–mass spectrometry methods for the quantitation of statins in biological samples

The 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA) reductase inhibitors, more commonly known as 'statins', are a novel class of drugs widely used for the treatment of hypercholesterolaemia in patients with established cardiovascular disease as well as those at high risk of developing atherosclerosis. Published chromatographic-mass spectrometric methods for the quantification of presently available seven statins, atorvastatin, simvastatin, lovastatin, pravastatin, fluvastatin, rosuvastatin and pitavastatin are reviewed. High performance liquid chromatography (HPLC) in combination with tandem mass spectrometry (MS/MS) is the analytical technique of choice for the quantification of statins in biological samples. This review envisages that most of the methods used for quantification of statins are in plasma and they are suitable for therapeutic drug monitoring of these drugs.

Rosuvastatin treatment prevents progressive kidney inflammation and fibrosis in stroke-prone rats

Salt-loaded, spontaneously hypertensive stroke-prone rats show progressive increases in blood pressure and proteinuria and accumulate acute-phase proteins in body fluids, modeling events during renal damage. The aim of this study was to assess the pathological events occurring in the kidney of spontaneously hypertensive stroke-prone rats over time and evaluate the effects of statin treatment, which is known to improve renal and cardiovascular outcomes. Kidneys of male spontaneously hypertensive stroke-prone rats euthanized at different stages of proteinuria showed progressive inflammatory cell infiltration, the accumulation of alpha-smooth muscle actin-positive cells, degenerative changes in podocytes, and severe fibrosis. These were accompanied by an imbalance in the plasminogen/plasmin and metalloprotease systems characterized by the increased renal expression of plasminogen activator inhibitor-1, tissue plasminogen activator, and urokinase plasminogen activator; the net result was an increase in plasmin and matrix metalloproteinase (MMP)-2 and a reduction in MMP-9 activity. Chronic treatment with the hydrophilic rosuvastatin had renoprotective effects in terms of morphology and inflammation and prevented the changes in plasmin, MMP-2, and MMP-9 activity. These effects were independent of the changes in blood pressure and plasma lipid levels. Treatment with the lipophilic simvastatin was not renoprotective. These data suggest that rosuvastatin may have potential utility as a therapeutic option in renal diseases that are characterized by inflammation and fibrosis.

A pravastatin dose-escalation study in systemic lupus erythematosus

Statin medications have been suggested for widespread use in patients with systemic lupus erythematosus (SLE). We studied the dose effectiveness and tolerability of pravastatin in SLE. We compared 41 SLE subjects in a two-month open-label dose-titration study of pravastatin to 22 SLE controls. Lipids, ALT, CPK, CRP, adverse effects were assessed. Linear mixed models assessed changes in lipids and CRP, comparing pravastatin subjects to controls. After 1 month of pravastatin 10 mg a day, total cholesterol decreased by 16% (+/-12.1%) and LDL by 24% (+/-17%), compared with 1.8% (+/-7.5%) and 2.6% (+/-8.6%) decreases in controls (P < 0.001). CRP did not decline. Glucocorticoids appeared to decrease pravastatin effectiveness. Serum CPK increased in one subject. Pravastatin reduced LDL and total cholesterol levels approximately the same degree observed in normal individuals, but the effect appeared blunted in those on modest doses of glucocorticoids and those with higher BMI.

Adverse Events With Concomitant Amiodarone and Statin Therapy

The authors reviewed adverse events (AEs) reported to the United States Food and Drug Administration to determine the percentage of statin-associated AE reports with concurrent amiodarone use for simvastatin, atorvastatin, and pravastatin. AEs affecting the following organ systems were analyzed: muscle, liver, pancreas, and bone marrow. The percentage of simvastatin reports with concurrent amiodarone use was 1.0%, compared with 0.7% of the atorvastatin-associated reports (p = not significant). The percentage of pravastatin reports with concurrent amiodarone use was 0.4% (p < 0.05 for pravastatin vs. simvastatin). Muscle toxicity was the most commonly reported statin-amiodarone AE, accounting for 77% of the reports. AEs tended to occur in older male patients (mean age, 76 years), who were on multiple other medications (mean number of other medications, five). Clinicians should be vigilant about muscle-related complaints in patients concomitantly taking amiodarone, especially in elderly patients on multiple medications. Use of a statin not metabolized through the cytochrome P450-3A4 system may be appropriate in this setting.

Lovastatin inhibits the extracellular-signal-regulated kinase pathway in immortalized rat brain neuroblasts

We have shown previously that lovastatin, a 3-hydroxy-3-methyl- glutaryl coenzyme A reductase inhibitor, induces apoptosis in spontaneously immortalized rat brain neuroblasts. In the present study, we analysed the intracellular signal transduction pathways by which lovastatin induces neuroblast apoptosis. We showed that lovastatin efficiently inhibited Ras activation, which was associated with a significant decrease in ERK1/2 (extracellular-signal-regulated kinase 1/2) phosphorylation. Lovastatin also decreased CREB phosphorylation and CREB-mediated gene expression. The effects of lovastatin on the Ras/ERK1/2/CREB pathway were time- and concentration-dependent and fully prevented by mevalonate. In addition, we showed that two MEK [MAPK (mitogen-activated protein kinase)/ERK kinase] inhibitors, PD98059 and PD184352, were poor inducers of apoptosis in serum-treated neuroblasts. However, these inhibitors significantly increased apoptosis induced by lovastatin treatment. Furthermore, we showed that pharmacological inhibition of both MEK and phosphoinositide 3-kinase activities was able to induce neuroblast apoptosis with similar efficacy as lovastatin. Our results suggest that lovastatin triggers neuroblast apoptosis by regulating several signalling pathways, including the Ras/ERK1/2 pathway. These findings might also contribute to elucidate the intracellular mechanisms involved in the central nervous system side effects associated with statin therapy.

Simultaneous quantification of atorvastatin and active metabolites in human plasma by liquid chromatography-tandem mass spectrometry using rosuvastatin as internal standard

A simple, sensitive, selective and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of atorvastatin and its active metabolites ortho-hydroxyatorvastatin and para-hydroxyatorvastatin in human plasma using rosuvastatin as internal standard (IS). Following simple liquid-liquid extraction, the analytes were separated using an isocratic mobile phase on a reversed-phase C18 column and analyzed by MS in the multiple reaction monitoring mode using the respective [M+H]+ ions, m/z 559/440 for atorvastatin, m/z 575/466 for ortho-hydroxyatorvastatin, m/z 575/440 for para-hydroxyatorvastatin and m/z 482/258 for the IS. The assay exhibited a linear dynamic range of 0.1-20 ng/mL for atorvastatin and its two metabolites in human plasma. The lower limit of quantification was 100 pg/mL with a relative standard deviation of less than 8%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The average absolute recoveries of atorvastatin, ortho-hydroxyatorvastatin, para-hydroxyatorvastatin and the IS from spiked plasma samples were 54.2 +/- 3.2, 50.1 +/- 3.8, 65.2 +/- 3.6 and 71.7 +/- 2.7%, respectively. A run time of 2.5 min for each sample made it possible to analyze more than 300 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability or bioequivalence studies.

The comparative safety of rosuvastatin: a retrospective matched cohort study in over 48,000 initiators of statin therapy

PURPOSE

The purpose of this study was to compare incidence rates of hospitalization associated with rhabdomyolysis, myopathy, renal, or hepatic dysfunction, and of in-hospital death, between initiators of rosuvastatin and other statins.

METHODS

This was a matched cohort study of statin initiators from the administrative database of a large health insurer in the US, during the first 6 months of rosuvastatin availability with up to 18 months of follow-up. All outcome events were verified by medical record review. Incidence rates, risk ratios, and associated 95% confidence intervals were estimated.

RESULTS

From an initial pool of 12,217, 11,249 eligible rosuvastatin initiators were matched to 37,282 initiators of other statins. The incidence rate (IR) per 1000 person-years for rhabdomyolysis was 0.10 [0.00, 0.55] for rosuvastatin initiators (n = 1) and 0.06 [0.01, 0.22] for other statin initiators (n = 2), for a hazard ratio (HR) of 1.98 [0.18, 21.90]. The IR for myopathy was 0.20 [0.02, 0.71] for rosuvastatin initiators (n = 2) and 0.00 [0.00, 0.09] for other statin initiators (n = 0). The IR for renal dysfunction was 1.18 [0.61, 2.06] for rosuvastatin initiators (n = 12) and 1.26 [0.91, 1.71] for other statin initiators (n = 42), for a HR of 0.90 [0.47, 1.73]. The IR for hepatic dysfunction was 0.20 (0.02, 0.71) for rosuvastatin initiators (n = 2) and 0.24 (0.10, 0.47) for other statin initiators (n = 8), for a HR of 0.87 (0.18, 4.14).

CONCLUSIONS

This study found no difference between rosuvastatin and the other statins in the incidence of hospitalizations associated with renal or hepatic events, or death. The absolute incidence rates of rhabdomyolysis and myopathy were reassuringly low among all statin initiators but remain too small for firm conclusions to be drawn on any difference between the statins.

Hepatic adverse drug reactions: a case/non-case study in Italy

OBJECTIVE

Adverse drug reactions (ADRs) can involve all tissues and organs. Liver injuries are considered among the most serious and are a cause for concern among physicians and patients. To assess the extent of drug-induced liver injuries in Italy we compared the number of cases of hepatic ADRs with reports of all other drug-related reactions present in the same database.

METHODS

Spontaneous reports from six Italian Regions collected from January 1990 to May 2005 were analysed. Adverse reactions were classified according to WHO Adverse Reaction Terminology for causality assessment, and only those with "certain", "probable" or "possible" causality assessment were included. Association between drugs and hepatic ADRs was assessed using the case/non case method, calculating the ADR reporting odds ratio (ROR) as a measure of disproportionality.

RESULTS

On May 2005, the database contained 35,767 ADR reports, of which 11,829 were excluded because they were unclassifiable or unlikely in terms of causality assessment. Therefore, the analysis was carried out on 23,938 reports, of which 1,069 concerned hepatic ADRs (cases) and 22,869 concerned non-cases. The proportion of serious ADRs was about 40% in the overall database, and about 74% among cases. The drug classes with the highest number of cases were statins (ROR = 2.9, 95% CI 2.4-3.5), antiplatelet agents (ROR = 3.5; 95% CI 2.6-4.6), NSAIDs (ROR = 2.9; 95% CI 2.1-3.9) and macrolides (ROR = 1.7; 95% CI 1.2-2.3).

CONCLUSION

Hepatic adverse drug reactions remain a serious concern for several drugs widely used in clinical practice. Monitoring hepatic enzymes on a monthly basis for the first 6 months of treatment has been suggested for patients taking medications known to be hepatotoxic. A better knowledge of the epidemiology and mechanisms of hepatic ADRs may contribute to minimising their occurrence.

Statin-induced rhabdomyolysis

Simvastatin and other HMG-CoA reductase inhibitors (statins) are one of the most frequently prescribed class of medications in the United States, with over 15 million Americans taking these drugs. Relatively rare adverse effects related to the known toxic effects of these drugs are more common than generally realized. Clinically significant statin-induced rhabdomyolysis is an uncommon but life-threatening adverse effect. We describe a case of simvastatin-induced rhabdomyolysis. Current knowledge of the pharmacology of the HMG-CoA reductase inhibitors and the drug interactions that potentiate these adverse effects are discussed. The clinical features of rhabdomyolysis and current treatment recommendations are presented.

Pharmacokinetic and pharmacodynamic alterations of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors: drug-drug interactions and interindividual differences in transporter and metabolic enzyme functions

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are widely used for the treatment of hypercholesterolemia. Their efficacy in preventing cardiovascular events has been shown by a large number of clinical trials. However, myotoxic side effects, sometimes severe, including myopathy or rhabdomyolysis, are associated with the use of statins. In some cases, such toxicity is associated with pharmacokinetic alterations. In this review, the pharmacokinetic aspects and physicochemical properties of statins are reviewed in order to understand the mechanism governing their pharmacokinetic alterations. Among the statins, simvastatin, lovastatin and atorvastatin are metabolized by cytochrome P450 3A4 (CYP3A4) while fluvastatin is metabolized by CYP2C9. Cerivastatin is subjected to 2 metabolic pathways mediated by CYP2C8 and 3A4. Pravastatin, rosuvastatin and pitavastatin undergo little metabolism. Their plasma clearances are governed by the transporters involved in the hepatic uptake and biliary excretion. Also for other statins, which are orally administered as open acid forms (i.e. fluvastatin, cerivastatin and atorvastatin), hepatic uptake transporter(s) play important roles in their clearances. Based on such information, pharmacokinetic alterations of statins can be predicted following coadministration of other drugs or in patients with lowered activities in drug metabolism and/or transport. We also present a quantitative analysis of the effect of some factors on the pharmacokinetics of statins based on a physiologically based pharmacokinetic model. To avoid a pharmacokinetic alteration, we need to have information about the metabolizing enzyme(s) and transporter(s) involved in the pharmacokinetics of statins and, along with such information, model-based prediction is also useful.

Statin safety: an overview and assessment of the data--2005

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statin drugs, have been studied in numerous controlled human research trials involving hundreds of thousands of study participants. Statins have been prescribed for millions of patients. Based on this vast research and clinical experience, statins have been shown to improve lipid blood levels and reduce atherosclerotic coronary artery disease (CAD) risk, resulting in reduced CAD morbidity and mortality, and in several studies, reduced overall ("all-cause") mortality. From a safety perspective, both research trial evidence and clinical practice experience have demonstrated that statins are generally well tolerated. However, as with all pharmaceuticals, safety considerations exist with both monotherapy and combination statin therapy, mainly involving potential adverse effects on muscle, liver, kidney, and the nervous system. The evidence supporting statin-related potential adverse experiences on these organ systems is sometimes strong and based on clear clinical trial evidence (such as the increased risk of muscle enzyme elevation with higher statin doses). The evidence is at other times more speculative, being based on case reports and inconclusive clinical trial data (such as possible favorable or unfavorable effects of statins on cognition). Because the use of statins is so widespread, it is useful for the clinician to understand statin safety issues and the level of available evidence supporting the contention that various adverse effects are caused by statins. This review presents an assessment of statin safety based on an overview of the current statin safety data and their clinical implications.

Effects of statins beyond lipid lowering: Potential for clinical benefits

BACKGROUND

The role of statin drugs in the reduction of serum lipids has been well documented. More recently, evidence suggesting that statins may positively impact many organ systems and disease states independent of lipid reduction has emerged. The term "pleiotropic effects" has been used to refer to these properties. We reviewed the evidence exploring such potential effects.

METHODS

A search of the MEDLINE database was conducted for articles published between 1985 to 2005 on the pleiotropic and the lipid-lowering independent effects of statin drugs. The search terms "statin", "HMG-CoA reductase inhibitor", "pleiotropic effects", and "inflammation" were used. English language articles were selected for inclusion along with selected cross-references.

RESULTS

Numerous animal and clinical studies support the presence of a spectrum of beneficial effects for statins that are independent of their lipid-lowering properties. These effects are mediated by a variety of mechanisms and they suggest that the therapeutic role of statins may expand.

CONCLUSION

Statins have shown great promise beyond their lipid-lowering effects. Ongoing and future studies will help to further clarify the potential clinical impact of these "pleiotropic effects".

The long-term course of low-density lipoprotein cholesterol after initiation of statin treatment: retrospective database analysis over 3 years in health maintenance organization enrollees

OBJECTIVES

Our primary objective was to obtain robust estimates of the low-density lipoprotein cholesterol (LDL-C) decrease from baseline over a long period (ie, 3 years) after initiation of statin treatment in a usual-care setting. Our secondary objective was to investigate the predictors of the LDL-C time course.

METHODS

We retrospectively analyzed the data for a sample of enrollees in a health maintenance organization (HMO) who started statin treatment between October 1, 1995, and December 31, 1998. Using the HMO's claims database, we examined the LDL-C change from baseline (as measured at the prescribing physicians' discretion) and computed mean estimates every 6 months up to 3 years. We investigated potential predictors of the LDL-C time course (ie, age, sex, baseline LDL-C, previous treatment, prescribing physician's specialty, and most recent treatment) with a mixed model applied to longitudinal data. This model enabled us to impute missing data for all enrollees still being followed, including those who had stopped treatment, and to discuss the robustness of our findings. We applied 2 methods of imputation, assuming either of the following: (1) data were missing at random but could be estimated from the parameters in the mixed model, or (2) LDL-C returned to the baseline value > or =15 days after treatment cessation.

RESULTS

We examined data from 3193 individuals. In most cases, the statin used was fluvastatin or pravastatin. The observed mean (95% CI) LDL-C decrease from baseline widened progressively from 23.6% (23.0%-24.3%) at 6 months to 28.0% (27.1%-28.9%) at 18 months and 30.2% (28.7%-31.7%) at 36 months after treatment initiation. These results remained robust after the imputation of missing data, with mean LDL-C reduction consistently >20% at each 6-month time point during the 3 years after treatment initiation. Variations as a function of baseline characteristics were limited (demographics) or explicable by extraneous factors (baseline LDL-C). There were predictable variations as a function of the most recent treatment.

CONCLUSIONS

This analysis indicates a long-term reduction in LDL-C among a sample of HMO enrollees who initiated statin treatment in a usual-care setting. The results were robust after imputation of missing data, with mean decrease from baseline consistently >20% over 3 years. However, given the retrospective design of our study and the absence of a control group, we cannot determine how much of the decrease was attributable to treatment.

Study on the conversion of three natural statins from lactone forms to their corresponding hydroxy acid forms and their determination in Pu-Erh tea

Conversions of statins, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, from lactone forms to their corresponding hydroxy acid form in 0.1 N NaOH or 0.05 N KOH (prepared with 25, 50, 75, 90% acetonitrile or methanol in water or 100% water) were evaluated. Results showed that lactone form statins could be transformed almost completely only in alkaline solutions prepared with 25 or 50% acetonitrile. In all methanolic alkaline solutions, lactone form statins could also be converted entirely, nevertheless, they would be further transformed to the methyl ester of the hydroxy acid form and the transformation increased as methanol rises. When lactone and hydroxy acid forms of statins were in methanol, ethyl acetate, 70% acetonitrile in water (with 0.5% acetic acid or no) for 0-48 h at room temperature or in 100 degrees C water for 0-2 h, lactone form statins were converted to their corresponding hydroxy acids, which were raised as time extends and the highest conversions of them were about 35% in 100 degrees C water and 70% acetonitrile, slightly transformed for lactone form statins in 70% acetonitrile (with 0.5% acetic acid) after 8 h, and the other treatments for all statins showed no significant changes. Interferences would be reduced efficiently when statins were extracted from Pu-Erh tea with methanol, ethyl acetate or 100 degrees C water followed by purifying through a C18 solid-phase extraction cartridge. Lovastatin was the only statin found in Pu-Erh tea and the highest content of it was found under ethyl acetate extraction. In ethyl acetate and methanol extracts, lovastatin existed merely as lactone form. The lowest content of lovastatin was found in the 100 degrees C water extract of Pu-Erh tea, however, both of lactone and hydroxy acid forms were found to exist in the extract.

Considerations in the treatment of dyslipidemia associated with chronic kidney failure and renal transplantation

In comparison to the general population, individuals with chronic kidney failure experience an increased risk for atherosclerotic cardiovascular disease attributed predominantly to pronounced abnormalities in lipid metabolism. The emerging consensus is that patients with chronic kidney failure should be treated aggressively for dyslipidemia. Statins reduce the risk of cardiovascular disease in a range of at-risk patients; this class of lipid-lowering drugs should be considered first-line treatment of dyslipidemia observed in renal disease patients. Although the statins share a common lipid-lowering effect, there are differences within this class of drugs. The statins differ in their pharmacokinetic effects, drug interaction profiles, and risk of myotoxicity. This article characterizes the dyslipidemia observed in the renal failure setting and reviews the therapeutic considerations involved in selecting among the statins. Lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, and rosuvastatin are the available statins in the United States.

Neuroinflammation: a potential therapeutic target

The increased appreciation of the importance of glial cell-propagated inflammation (termed 'neuroinflammation') in the progression of pathophysiology for diverse neurodegenerative diseases, has heightened interest in the rapid discovery of neuroinflammation-targeted therapeutics. Efforts include searches among existing drugs approved for other uses, as well as development of novel synthetic compounds that selectively downregulate neuroinflammatory responses. The use of existing drugs to target neuroinflammation has largely met with failure due to lack of efficacy or untoward side effects. However, the de novo development of new classes of therapeutics based on targeting selective aspects of glia activation pathways and glia-mediated pathophysiologies, versus targeting pathways of quantitative importance in non-CNS inflammatory responses, is yielding promising results in preclinical animal models. The authors briefly review selected clinical and preclinical data that reflect the prevailing approaches targeting neuroinflammation as a pathophysiological process contributing to onset or progression of neurodegenerative diseases. The authors conclude with opinions based on recent experimental proofs of concept using preclinical animal models of pathophysiology. The focus is on Alzheimer's disease, but the concepts are transferrable to other neurodegenerative disorders with an inflammatory component.