The myotoxicity of statins

Safety of Combined Statin and Fibrate Therapy: Risks of Liver Injury and Acute Kidney Injury in a Cohort Study from the Shizuoka Kokuho Database

INTRODUCTION

Statins and fibrates are important means of preventing cardiovascular diseases, particularly when administered in combination as part of various therapeutic strategies. In this study, we explored the risks associated with various combinations of these drugs.

OBJECTIVE

We aimed to evaluate the risk of 1-year hospitalization with acute kidney injury, liver injury, pancreatitis, or rhabdomyolysis related to the concurrent administration of statins and fibrates.

METHODS

We performed a retrospective cohort study using data from the Shizuoka Kokuho Database, focusing on patients prescribed statins, fibrates, or a combination. Four drug exposure patterns were evaluated: adding statins to fibrates (exposure 1), switching from fibrates to statins (exposure 2), adding fibrates to statins (exposure 3), and switching from statins to fibrates (exposure 4). Hospitalization for the specified conditions within 1 year was the outcome. Propensity score matching was used to create balanced cohorts for comparison.

RESULTS

We studied 269,226 statin users and 16,282 fibrate users. After propensity score matching, there were 498 participants in the group of exposure 1, matched with 2988 in the fibrate-only group; 1180 in the group of exposure 2, matched with 7080 in the fibrate-only group; 1183 in group of exposure 3, matched with 11,830 in the statin only group; and 1356 in group of exposure 4, matched with 13,560 in the statin only group. The 1-year hospitalization rate with liver injury was higher in the group of exposure 1 than in the fibrate-only group (1.2% vs 0.3%, p < 0.01), in the group of exposure 2 than in the fibrate-only group (0.9% vs 0.3%, p < 0.01), and in the group of exposure 4 than in the statin-only group (0.6% vs 0.2%, p = 0.02). There was also a higher risk of 1-year hospitalization with acute kidney injury in group of exposure 1 than in the fibrate-only group (1.3% vs 0.3%, p = 0.01) but not in evaluations of exposure 2, 3, and 4. However, there were no differences in the risks of 1-year hospitalization with pancreatitis or rhabdomyolysis among the matched groups.

CONCLUSIONS

We have demonstrated higher risks of 1-year hospitalization with liver injury or acute kidney injury associated with the use of combinations of statins and fibrates. This underscores the need for a cautious approach to the prescribing of such drug combinations and the importance of monitoring patients for potential adverse events.

Toxic Myopathies

PURPOSE OF REVIEW

This article reviews the pathogenesis, clinical features, and management of toxic myopathy related to common medications, critical illness, and illicit substances.

RECENT FINDINGS

Muscle symptoms are common among statin users and are usually reversible after discontinuation of the statin; rarely, however, statins trigger an immune-mediated necrotizing myopathy that persists and requires immunomodulatory therapy. Autoantibodies targeting 3-hydroxy-3-methylglutaryl coenzyme A reductase can distinguish the toxic and immune-mediated forms. Immune checkpoint inhibitors, increasingly used in the treatment of advanced cancer, have recently been associated with the development of inflammatory myositis. A reversible mitochondrial myopathy has long been associated with zidovudine, but recent reports elucidate the risk of myopathy with newer antivirals, such as telbivudine and raltegravir.

SUMMARY

The medications most commonly associated with myopathy include statins, amiodarone, chloroquine, hydroxychloroquine, colchicine, certain antivirals, and corticosteroids, and myopathy can occur with chronic alcoholism. Certain clinical, electrodiagnostic, and histologic features can aid in early recognition. Stopping the use of the offending agent reverses symptoms in most cases, but specific and timely treatment may be required in cases related to agents that trigger immune-mediated muscle injury.

Clinically relevant drug interactions between statins and antidepressants

WHAT IS KNOWN AND OBJECTIVE

Statins, also known as 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, and antidepressant drugs are frequently used in combination due to the high and growing incidence of cardiovascular diseases and psychiatric disorders worldwide. Several aspects on management, the risk of adverse events (AEs) occurrence and the potential clinically relevant pharmacokinetic (PK) and pharmacodynamic (PD) drug-drug interactions (DDIs) between these two classes have not been well investigated. The aim of the present review was to describe the PK and PD interactions, of clinical relevance, between statins and antidepressant drugs and provide a comprehensive overview of their pharmacological features for appropriate multiple drug regimens.

METHODS

Relevant studies were identified through a literature search of PubMed and the Cochrane databases focusing on clinically relevant DDIs between statins and antidepressants. Only papers in English were included in the search.

RESULTS AND DISCUSSION

Pharmacodynamic (PD) drug-drug interactions (DDIs) are unlikely to occur as statins are highly selective inhibitors of HMG-CoA reductase with no relevant effect on other enzymes or receptor systems. Despite the numerous PK studies on individual drugs belonging to statins and antidepressant agents, only a few case reports regarding specific DDIs are present in the literature and no clinical studies have been performed. PK data allow to speculate on potential DDIs, comparing the metabolic pathways, intestinal and liver transporters and elimination routes. Overall, second-generation antidepressants, in particular citalopram, escitalopram, mirtazapine, reboxetine and venlafaxine, have weak inhibitory effects on various cytochrome (CYP) isozymes and seem to have a more advantageous DDIs profile in vivo. Conversely, nefazodone, fluoxetine, paroxetine and fluvoxamine influence considerably CYPs activity with potential effects on statins plasma levels, although pravastatin, pitavastatin and rosuvastatin are not susceptible to inhibition by any CYP. Albeit no studies have been performed on P-glycoprotein (P-gp), interactions of clinical relevance are unlikely.

WHAT IS NEW AND CONCLUSION

Although DDIs with antidepressants are potentially, but rarely clinically significant, the use of antidepressants with a more favourable drug interaction profile is advisable. An evaluation on DDIs between these drugs can be useful for future PK/PD studies on drug-drug interaction to provide clinicians with more data for appropriate multiple drug regimens.

Optimizing the Pharmacological Profile of New Bifunctional Antihyperlipidemic/Antioxidant Morpholine Derivatives

Among the causal risk factors directly promoting the development of coronary and peripheral atherosclerosis are reactive oxygen species and elevated low-density lipoprotein plasma levels. We hereby designed new potent squalene synthase (SQS) inhibitors that may simultaneously tackle the oxidative stress induced by lipid peroxidation. Using previously developed morpholine derivatives as a starting point, we conducted extensive structural changes by either substituting or modifying the morpholine ring, aiming at an optimal SQS-antioxidant pharmacological profile. Compounds 2, 3, and 7 emerged as the most potent bifunctional analogues, displaying IC₅₀ values for SQS inhibition of 0.014, 0.16, and 0.51 μΜ, respectively, and further significantly decreasing lipid peroxidation of hepatic microsomal membranes. The aforementioned activities were also confirmed in vivo since the most promising derivative 2 exhibited a remarkable antihyperlipidemic and antioxidant effect. In conclusion, rational drug design accompanied by structure-activity relationship studies led to compounds combining improved antioxidant and antihyperlipidemic activity that may serve as multifunctional agents against atherosclerosis.

Effects of naturally-produced lovastatin on feed digestibility, rumen fermentation, microbiota and methane emissions in goats over a 12-week treatment period

Twenty male Saanen goats were randomly assigned to four levels of lovastatin supplementation and used to determine the optimal dosage and sustainability of naturally produced lovastatin from fermentation of palm kernel cake (PKC) with Aspergillus terreus on enteric methane (CH₄) mitigation. The effects on ruminal microbiota, rumen fermentation, feed digestibility and health of animal were determined over three measuring periods (4-, 8- and 12-weeks) and the accumulation of lovastatin in tissues was determined at the end of the experiment. The diets contained 50% rice straw, 22.8% concentrates and 27.2% of various proportions of untreated or treated PKC to achieve the target daily intake level of 0 (Control), 2, 4 or 6 mg lovastatin/kg body weight (BW). Enteric CH₄ emissions per dry matter intake (DMI), decreased significantly (P<0.05) and equivalent to 11% and 20.4%, respectively, for the 2 and 4 mg/kg BW groups as compared to the Control. No further decrease in CH₄ emission thereafter with higher lovastatin supplementation. Lovastatin had no effect on feed digestibility and minor effect on rumen microbiota, and specifically did not reduce the populations of total methanogens and Methanobacteriales (responsible for CH₄ production). Similarly, lovastatin had little effect on rumen fermentation characteristics except that the proportion of propionate increased, which led to a decreasing trend (P<0.08) in acetic: propionate ratio with increasing dosage of lovastatin. This suggests a shift in rumen fermentation pathway to favor propionate production which serves as H⁺ sink, partly explaining the observed CH₄ reduction. No adverse physiological effects were noted in the animals except that treated PKC (containing lovastatin) was less palatable at the highest inclusion level. Lovastatin residues were detected in tissues of goats fed 6 mg lovastatin/kg BW at between 0.01 to 0.03 μg/g, which are very low.

A short-term statin treatment changes the contractile properties of fast-twitch skeletal muscles

Background

Cumulative evidence indicates that statins induce myotoxicity. However, the lack of understanding of how statins affect skeletal muscles at the structural, functional, and physiological levels hampers proper healthcare management. The purpose of the present study was to investigate the early after-effects of lovastatin on the slow-twitch soleus (Sol) and fast-twitch extensor digitorum longus (EDL) muscles.

Methods

Adult C57BL/6 mice were orally administrated with placebo or lovastatin [50 mg/kg/d] for 28 days. At the end of the treatment, the isometric ex vivo contractile properties of the Sol and EDL muscles were measured. Subtetanic and tetanic contractions were assessed and contraction kinetics were recorded. The muscles were then frozen for immunohistochemical analyses. Data were analyzed by two-way ANOVA followed by an a posteriori Tukey’s test.

Results

The short-term lovastatin treatment did not induce muscle mass loss, muscle fiber atrophy, or creatine kinase (CK) release. It had no functional impact on slow-twitch Sol muscles. However, subtetanic stimulations at 10 Hz provoked greater force production in fast-twitch EDL muscles. The treatment also decreased the maximal rate of force development (dP/dT) of twitch contractions and prolonged the half relaxation time (1/2RT) of tetanic contractions of EDL muscles.

Conclusions

An early short-term statin treatment induced subtle but significant changes in some parameters of the contractile profile of EDL muscles, providing new insights into the selective initiation of statin-induced myopathy in fast-twitch muscles.

Statin-Induced Myopathy: The Two Faces of Janus

Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) have been shown to be effective at lowering low-density lipoprotein cholesterol and decreasing the risk of coronary heart disease. Although safe and well tolerated by most patients, statins have also been associated with muscle-related adverse events. This article reviews statin-associated myotoxicity to clarify the definitions of muscle-related adverse events and discusses their incidences in major statin trials, case reports, and review articles through January 2006. Milder complaints (ie, myalgia) are reported by approximately 5% to 7% of patients who take statins. More severe myotoxicity, namely rhabdomyolysis, is extremely rare for all statins save cerivastatin, and most recent estimates of its incidence are between 0.44 and 0.54 cases per 10 000 person-years. The mechanism of statin-associated myotoxicity has not been satisfactorily defined and is likely due to multiple factors, including membrane instability, mitochondrial dysfunction, and defects in myocyte duplication

Skeletal Muscle Susceptibility to Clofibrate Induction of Lesions in Rats

Morphological changes induced by clofibrate in type-1 predominant soleus, type-2 predominant tensor fasciae latae, and type-1 and -2 mixed biceps femoris muscles and diaphragm in rats were investigated. Administration of the agent at 500 or 750 mg/kg/day by oral gavage for 14 or 28 days caused lesions in the soleus muscle and diaphragm, bur no changes in the tensor fasciae latae and biceps femoris muscles. In soleus muscle, vacuolation of muscle fibers was observed in all animals treated with clofibrate, and degeneration of muscle fibers and infiltration of leukocytes were noted at 750 mg/kg/day. In diaphragm, vacuolation of muscle fibers was also observed in all animals treated with clofibrate, and these lesions were located in type-1 skeletal muscles densely stained with NADH-TR. The vacuoles seen in soleus muscle and diaphragm were positive for oil red O staining. In addition, increase of lipid droplets and mitochondrial hypertrophy was seen in soleus muscle, ultrastructurally. These data suggest that sensitivity to clofibrate-induced muscle toxicity differs among muscles, with type-1 fibers being susceptible.

Muscle rupture associated with statin use

AIM

Statins are used in the treatment of hyperlipidaemia. They are among the most commonly prescribed drugs worldwide. Statins have been linked to musculoskeletal adverse drug reactions. However muscle rupture has not been discussed as an adverse drug reaction to statins so far. The aim of this article is to give an overview of cases of muscle rupture associated with the use of statins.

METHOD

We analyzed the cases of muscle rupture associated with the use of statins that were collected by the Netherlands Pharmacovigilance Centre Lareb complemented with the review of cases from the EudraVigilance database.

RESULTS

Fifteen cases of muscle rupture associated with statin use have been identified in the database of the Netherlands Pharmacovigilance Centre. Overall, there was a plausible temporal association of events in most cases. In addition, the EudraVigilance database contained 165 reports of muscle rupture reported in patients using statins. Muscle rupture was disproportionally associated with statin use in both databases. The reporting odds ratio was 23.4 (95% CI 11.9, 46.0) and 14.6 (95% CI 12.3, 17.2), respectively.

CONCLUSION

Data from spontaneous reporting systems suggest that use of statins is associated with muscle rupture. Physicians and patients should be aware that this can occur.

Structural effects of simvastatin on liver rat [corrected] tissue: Fourier transform infrared and Raman microspectroscopic studies

Simvastatin is one of the most frequently prescribed statins because of its efficacy in the treatment of hypercholesterolemia, reducing cardiovascular risk and related mortality. Determination of its side effects on different tissues is mandatory to improve safe use of this drug. In the present study, the effects of simvastatin on molecular composition and structure of healthy rat livers were investigated by Fourier transform infrared and Raman imaging. Simvastatin-treated groups received 50 mg/kg/day simvastatin for 30 days. The ratio of the area and/or intensity of the bands assigned to lipids, proteins, and nucleic acids were calculated to get information about the drug-induced changes in tissues. Loss of unsaturation, accumulation of end products of lipid peroxidation, and alterations in lipid-to-protein ratio were observed in the treated group. Protein secondary structure studies revealed significant decrease in α-helix and increase in random coil, while native β-sheet decreases and aggregated β-sheet increases in treated group implying simvastatin-induced protein denaturation. Moreover, groups were successfully discriminated using principal component analysis. Consequently, high-dose simvastatin treatment induces hepatic lipid peroxidation and changes in molecular content and protein secondary structure, implying the risk of liver disorders in drug therapy.

Exosomes derived from atorvastatin-modified bone marrow dendritic cells ameliorate experimental autoimmune myasthenia gravis by up-regulated levels of IDO/Treg and partly dependent on FasL/Fas pathway

Background

Previously, we have demonstrated that spleen-derived dendritic cells (DCs) modified with atorvastatin suppressed immune responses of experimental autoimmune myasthenia gravis (EAMG). However, the effects of exosomes derived from atorvastatin-modified bone marrow DCs (BMDCs) (statin-Dex) on EAMG are still unknown.

Methods

Immunophenotypical characterization of exosomes from atorvastatin- and dimethylsulfoxide (DMSO)-modified BMDCs was performed by electron microscopy, flow cytometry, and western blotting. In order to investigate whether statin-DCs-derived exosomes (Dex) could induce immune tolerance in EAMG, we administrated statin-Dex, control-Dex, or phosphate-buffered saline (PBS) into EAMG rats via tail vein injection. The tracking of injected Dex and the effect of statin-Dex injection on endogenous DCs were performed by immunofluorescence and flow cytometry, respectively. The number of Foxp3⁺ cells in thymuses was examined using immunocytochemistry. Treg cells, cytokine secretion, lymphocyte proliferation, cell viability and apoptosis, and the levels of autoantibody were also carried out to evaluate the effect of statin-Dex on EAMG rats. To further investigate the involvement of FasL/Fas in statin-Dex-induced apoptosis, the underlying mechanisms were studied by FasL neutralization assays.

Results

Our data showed that the systemic injection of statin-Dex suppressed the clinical symptoms of EAMG rats. These statin-Dex had immune regulation functions in immune organs, such as the spleen, thymus, and popliteal and inguinal lymph nodes. Furthermore, statin-Dex exerted their immunomodulatory effects in vivo by decreasing the expression of CD80, CD86, and MHC class II on endogenous DCs. Importantly, the therapeutic effects of statin-Dex on EAMG rats were associated with up-regulated levels of indoleamine 2,3-dioxygenase (IDO)/Treg and partly dependent on FasL/Fas pathway, which finally resulted in decreased synthesis of anti-R97–116 IgG, IgG2a, and IgG2b antibodies.

Conclusions

Our data suggest that atorvastatin-induced immature BMDCs are able to secrete tolerogenic Dex, which are involved in the suppression of immune responses in EAMG rats. Importantly, our study provides a novel cell-free approach for the treatment of autoimmune diseases.

Neutral endopeptidase-resistant C-type natriuretic peptide variant represents a new therapeutic approach for treatment of fibroblast growth factor receptor 3-related dwarfism

Achondroplasia (ACH), the most common form of human dwarfism, is caused by an activating autosomal dominant mutation in the fibroblast growth factor receptor-3 gene. Genetic overexpression of C-type natriuretic peptide (CNP), a positive regulator of endochondral bone growth, prevents dwarfism in mouse models of ACH. However, administration of exogenous CNP is compromised by its rapid clearance in vivo through receptor-mediated and proteolytic pathways. Using in vitro approaches, we developed modified variants of human CNP, resistant to proteolytic degradation by neutral endopeptidase, that retain the ability to stimulate signaling downstream of the CNP receptor, natriuretic peptide receptor B. The variants tested in vivo demonstrated significantly longer serum half-lives than native CNP. Subcutaneous administration of one of these CNP variants (BMN 111) resulted in correction of the dwarfism phenotype in a mouse model of ACH and overgrowth of the axial and appendicular skeletons in wild-type mice without observable changes in trabecular and cortical bone architecture. Moreover, significant growth plate widening that translated into accelerated bone growth, at hemodynamically tolerable doses, was observed in juvenile cynomolgus monkeys that had received daily subcutaneous administrations of BMN 111. BMN 111 was well tolerated and represents a promising new approach for treatment of patients with ACH.

Translational insight into statin-induced muscle toxicity: from cell culture to clinical studies

Statins are lipid-lowering drugs used widely to prevent and treat cardiovascular and coronary heart diseases. These drugs are among the most commonly prescribed medicines intended for long-term use. In general, statins are well tolerated. However, muscular adverse effects appear to be the most common obstacle that limits their use, resulting in poor patient compliance or even drug discontinuation. In addition, rare but potentially fatal cases of rhabdomyolysis have been reported with the use of these drugs, especially in the presence of certain risk factors. Previous reports have investigated statin-induced myotoxicity in vivo and in vitro using a number of cell lines, muscle tissues, and laboratory animals, in addition to randomized clinical trials, observational studies, and case reports. None of them have compared directly results from laboratory investigations with clinical observations of statin-related muscular adverse effects. To the best of our knowledge this is the first review article that combines laboratory investigation with clinical aspects of statin-induced myotoxicity. By reviewing published literature of in vivo, in vitro, and clinically relevant studies of statin myotoxicity, we aim to translate this important drug-related problem to establish a clear picture of proposed mechanisms that explain the risk factors and describe the diagnostic approaches currently used for evaluating the degree of muscle damage induced by these agents. This review provides baseline novel translational insight that can be used to enhance the safety profile, to minimize the chance of progression of these adverse effects to more severe and potentially fatal rhabdomyolysis, and to improve the overall patient compliance and adherence to long-term statin therapy.

Combination therapy with ezetimibe and simvastatin to achieve aggressive LDL reduction

A low-density lipoprotein (LDL) cholesterol goal of less than 100 mg/dl is recommended for patients at moderate to high risk of cardiovascular disease with an optional LDL goal of less than 70 mg/dl for patients at a very high risk of cardiovascular disease. Most patients will require reductions in LDL of more than 50% in order to achieve these more aggressive goals. Only a few agents will lower LDL by at least 50%. This review will focus on the efficacy and safety ezetimibe/simvastatin coadministered as a therapy with enhanced LDL-lowering efficacy, while minimizing the adverse effects of statins in a wide range of patients. Ezetimibe 10 mg/simvastatin 80 mg lowers LDL by approximately 60% and has been demonstrated to be superior to the highest doses of atorvastatin and rosuvastatin for lowering LDL and raising high-density lipoprotein.

Potential role for statins in sickle cell disease

The complex pathophysiology of sickle cell disease (SCD) is remarkably similar to that observed in other chronic vascular diseases and involves multiple biologic pathways triggered by ischemia reperfusion injury, coagulation activation, and inflammation. Statins are potent lipid-lowering agents commonly used to reduce the risk of cardiovascular disease. Independent of their lipid lowering effect, statins have been shown to down-regulate inflammatory mediators and endothelial adhesion molecules, reduce tissue factor expression and restore nitric oxide bioavailability. The pleiotropic effects of statins make these agents attractive therapeutic candidates for SCD. This article reviews available evidence for the potential role of statins in SCD.

Atorvastatin-modified dendritic cells in vitro ameliorate experimental autoimmune myasthenia gravis by up-regulated Treg cells and shifted Th1/Th17 to Th2 cytokines

Conventional therapies for autoimmune diseases produce nonspecific immune suppression, which are usually continued lifelong to maintain disease control, and associated with a variety of adverse effects. In this study, we found that spleen-derived dendritic cells (DCs) from the ongoing experimental autoimmune myasthenia gravis (EAMG) rats can be induced into tolerogenic DCs by atorvastatin in vitro. Administration of these tolerogenic DCs to EAMG rats on days 5 and 13 post immunization (p.i.) resulted in improved clinical symptoms, which were associated with increased numbers of CD4(+)CD25(+) T regulatory (Treg) cells and Foxp3 expression, decreased lymphocyte proliferation among lymph node mononuclear cells (MNC), shifted cytokine profile from Th1/Th17 to Th2 type cytokines, decreased level of anti-R97-116 peptide (region 97-116 of the rat acetylcholine receptor α subunit) IgG antibody in serum. These tolerogenic DCs can migrate to spleen, thymus, popliteal and inguinal lymph nodes after they were injected into the EAMG rats intraperitoneally. Furthermore, these tolerogenic DCs played their immunomodulatory effects in vivo mainly by decreased expression of CD86 and MHC class II on endogenous DCs. All these data provided us a new strategy to treat EAMG and even human myasthenia gravis (MG).

Atorvastatin up-regulate toxicologically relevant genes in rainbow trout gills

There are large and increasing discharges of statins into the aquatic environment. Statins are cholesterol-lowering pharmaceuticals, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase, an enzyme in the cholesterol synthesis pathway. Earlier studies have shown that statins will affect the expression of a range of genes in mammalian tissues and this group of pharmaceuticals has also been shown to affect membrane transporters. Changes in gene expression and ion transport in aquatic organisms may have dramatic consequences for the individual. The aim of the present study was to clarify whether waterborne exposure to a selected statin, atorvastatin, would affect gene expression in rainbow trout (Oncorhynchus mykiss) gill or liver or ion regulation in gills. Juvenile rainbow trout were exposed to two atorvastatin acid and atorvastatin lactone concentrations for 7 days (nominal concentrations 200 ng L(-1) and 10 μg L(-1)). The exposures caused up-regulated gene expression in gill, not liver, and only at the lowest concentration. Genes involved in membrane transport (pgp, mrp1), oxidative stress response (sod, mt), apoptosis (bax) and biotransformation (sult2b) were differentially expressed whereas the expression of genes involved in cholesterol biosynthesis (hmgr, fdps) or peroxisomal proliferation (ppar) were not affected. There were no significant changes in gill Na(+)/K(+) ATPase activity following exposure to atorvastatin. The pattern of differentially expressed genes in rainbow trout gills differ from responses previously observed in mammalian tissues following statin exposure.

Long-term follow-up of statin treatment in a cohort of children with familial hypercholesterolemia: efficacy and tolerability

BACKGROUND

Early identification of children with familial hypercholesterolemia (FH) makes it possible to start lipid-lowering therapy at a young age in order to prevent cardiovascular disease. Numerous randomized, often placebo-controlled, studies have assessed the efficacy and safety of statins in children with FH.

OBJECTIVE

The aim of this pragmatic observational study was to evaluate pravastatin treatment efficacy and tolerability for a long period of time, and to assess how these results translate in 'real-life' clinical practice.

METHODS

We analyzed all medical files of young hypercholesterolemic patients referred to two specialized French centers. This population of 185 pravastatin-treated children with FH, with a mean baseline cholesterol level above 300 mg/dL, in most of whom genetic diagnosis was achieved, was followed-up for a mean duration of 2 years 2 months. The mean age for starting pravastatin was 11 years; in one of five children, treatment was started before the age of 8 years, mostly because of severe hypercholesterolemia or a family history of coronary heart disease.

RESULTS

A 16.9-19.2% decrease in total cholesterol level (21-24% for low-density lipoprotein cholesterol) was observed. Growth and puberty were not affected by statin treatment. A review of the medical files showed that 13% of children had side effects, most of which were minor; four of these children had muscular symptoms possibly related to the treatment. This frequency is lower than that observed in adults, and comparable to other studies in children.

CONCLUSIONS

In this large cohort of FH children, the efficacy and tolerability of pravastatin therapy in real-life conditions was demonstrated to be similar to that in randomized controlled studies.

Statin or fibrate chronic treatment modifies the proteomic profile of rat skeletal muscle

Statins and fibrates can cause myopathy. To further understand the causes of the damage we performed a proteome analysis in fast-twitch skeletal muscle of rats chronically treated with different hypolipidemic drugs. The proteomic maps were obtained from extensor digitorum longus (EDL) muscles of rats treated for 2-months with 10mg/kg atorvastatin, 20 mg/kg fluvastatin, 60 mg/kg fenofibrate and control rats. The proteins differentially expressed were identified by mass spectrometry and further analyzed by immunoblot analysis. We found a significant modification in 40 out of 417 total spots analyzed in atorvastatin treated rats, 15 out of 436 total spots in fluvastatin treated rats and 21 out of 439 total spots in fenofibrate treated rats in comparison to controls. All treatments induced a general tendency to a down-regulation of protein expression; in particular, atorvastatin affected the protein pattern more extensively with respect to the other treatments. Energy production systems, both oxidative and glycolytic enzymes and creatine kinase, were down-regulated following atorvastatin administration, whereas fenofibrate determined mostly alterations in glycolytic enzymes and creatine kinase, oxidative enzymes being relatively spared. Additionally, all treatments resulted in some modifications of proteins involved in cellular defenses against oxidative stress, such as heat shock proteins, and of myofibrillar proteins. These results were confirmed by immunoblot analysis. In conclusions, the proteomic analysis showed that either statin or fibrate administration can modify the expression of proteins essential for skeletal muscle function suggesting potential mechanisms for statin myopathy.

Synthesis of novel benzocoumarin derivatives as lipid lowering agents

A series of novel benzocoumarin derivatives were synthesized and evaluated for their in vivo anti-dyslipidemic and in vitro antioxidant activities. Preliminary screening indicates compound 4 as potential lead with significant lipid lowering and antioxidant activities. The study revealed that such attempts on benzocoumarin-based pharmacophores which is a biologically important scaffold might result in identification of new lead for anti-dyslipidemia.

Human skeletal muscle drug transporters determine local exposure and toxicity of statins

RATIONALE

The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, are important drugs used in the treatment and prevention of cardiovascular disease. Although statins are well tolerated, many patients develop myopathy manifesting as muscle aches and pain. Rhabdomyolysis is a rare but severe toxicity of statins. Interindividual differences in the activities of hepatic membrane drug transporters and metabolic enzymes are known to influence statin plasma pharmacokinetics and risk for myopathy. Interestingly, little is known regarding the molecular determinants of statin distribution into skeletal muscle and its relevance to toxicity.

OBJECTIVE

We sought to identify statin transporters in human skeletal muscle and determine their impact on statin toxicity in vitro.

METHODS AND RESULTS

We demonstrate that the uptake transporter OATP2B1 (human organic anion transporting polypeptide 2B1) and the efflux transporters, multidrug resistance-associated protein (MRP)1, MRP4, and MRP5 are expressed on the sarcolemmal membrane of human skeletal muscle fibers and that atorvastatin and rosuvastatin are substrates of these transporters when assessed using a heterologous expression system. In an in vitro model of differentiated, primary human skeletal muscle myoblast cells, we demonstrate basal membrane expression and drug efflux activity of MRP1, which contributes to reducing intracellular statin accumulation. Furthermore, we show that expression of human OATP2B1 in human skeletal muscle myoblast cells by adenoviral vectors increases intracellular accumulation and toxicity of statins and such effects were abrogated when cells overexpressed MRP1.

CONCLUSIONS

These results identify key membrane transporters as modulators of skeletal muscle statin exposure and toxicity.

Low dose simvastatin induces compositional, structural and dynamic changes in rat skeletal extensor digitorum longus muscle tissue

Statins are commonly used drugs in the treatment of hypercholesterolaemia. There are many adverse effects of statins on skeletal muscle, but the underlying mechanisms remain unclear. In the present study, the effects of low dose (20 mg/kg) simvastatin, a lipophilic statin, on rat EDL muscle (extensor digitorum longus muscle) were investigated at the molecular level using FTIR (Fourier-transform infrared) spectroscopy. FTIR spectroscopy allows us rapid and sensitive determination of functional groups belonging to proteins, lipids, carbohydrates and nucleic acids simultaneously. The results revealed that simvastatin treatment induces a significant decrease in lipid, nucleic acid, protein and glycogen content. A significant increase in the lipid/protein and nucleic acid/protein ratios was also obtained with simvastatin treatment. Furthermore, an increase in lipid order and membrane fluidity was detected. A decrease in the bandwidth of the amide I band and shifting of the position of this band to higher frequency values in treated muscle indicates structural changes in proteins. Detailed secondary structure analysis of the amide I band revealed a significant increase in antiparallel and aggregated beta-sheet, random coil structure and a significant decrease in beta-sheet structure, which indicates protein denaturation.

Rhabdomyolysis in community acquired bacterial sepsis--a retrospective cohort study

Background and Objectives

Rhabdomyolysis is often associated with sepsis and gram positive bacterial pathogens are reported to be the most frequent cause of sepsis induced rhabdomyolysis. We report the pattern of infecting bacterial pathogens and associated causal factors in a South-Indian cohort.

Design, Setting, Participants & Measurements

Retrospective cohort study of adult patients with community acquired bacterial sepsis complicated by rhabdomyolysis from March 2003 - August 2008. Rhabdomyolysis was defined as serum creatine kinase >2000 IU/L. The study population was divided into group-I (sepsis with gram positive pathogens), group–II (sepsis with gram negative pathogens) and group-III (culture negative sepsis).

Results

103 patients (group I -15, group II- 34 and group III- 54) formed the study cohort. Mean age was 55 years and two-third had diabetes. Mean creatine kinase was 7114 IU/L and mean serum creatinine on admission was 2.4 mg/dl. Causative pathogen of sepsis was identified in 47.5%. Gram negative pathogens were more frequently (33%) associated with rhabdomyolysis than gram positive pathogens (14.5%). Lung was the commonest foci of sepsis (38.8%). 78.6% of the study population had one or more additional causal factor for rhabdomyolysis like statin intake, chronic alcoholism, hypokalemia, hypernatremia and hypophosphatemia. Mortality was 59%.

Conclusions

Gram negative bacterial pathogens were more frequently associated with rhabdomyolysis than gram positive pathogens. Rhabdomyolysis in patients with sepsis is multifactorial and is associated with high mortality.

Association between statin-associated myopathy and skeletal muscle damage

BACKGROUND

Many patients taking statins often complain of muscle pain and weakness. The extent to which muscle pain reflects muscle injury is unknown.

METHODS

We obtained biopsy samples from the vastus lateralis muscle of 83 patients. Of the 44 patients with clinically diagnosed statin-associated myopathy, 29 were currently taking a statin, and 15 had discontinued statin therapy before the biopsy (minimal duration of discontinuation 3 weeks). We also included 19 patients who were taking statins and had no myopathy, and 20 patients who had never taken statins and had no myopathy. We classified the muscles as injured if 2% or more of the muscle fibres in a biopsy sample showed damage. Using reverse transcriptase polymerase chain reaction, we evaluated the expression levels of candidate genes potentially related to myocyte injury.

RESULTS

Muscle injury was observed in 25 (of 44) patients with myopathy and in 1 patient without myopathy. Only 1 patient with structural injury had a circulating level of creatine phosphokinase that was elevated more than 1950 U/L (10x the upper limit of normal). Expression of ryanodine receptor 3 was significantly upregulated in patients with biopsy evidence of structural damage (1.7, standard error of the mean 0.3).

INTERPRETATION

Persistent myopathy in patients taking statins reflects structural muscle damage. A lack of elevated levels of circulating creatine phosphokinase does not rule out structural muscle injury. Upregulation of the expression of ryanodine receptor 3 is suggestive of an intracellular calcium leak.

Preclinical characteristics of the hepatitis C virus NS3/4A protease inhibitor ITMN-191 (R7227)

Future treatments for chronic hepatitis C virus (HCV) infection are likely to include agents that target viral components directly. Here, the preclinical characteristics of ITMN-191, a peptidomimetic inhibitor of the NS3/4A protease of HCV, are described. ITMN-191 inhibited a reference genotype 1 NS3/4A protein in a time-dependent fashion, a hallmark of an inhibitor with a two-step binding mechanism and a low dissociation rate. Under preequilibrium conditions, 290 pM ITMN-191 half-maximally inhibited the reference NS3/4A protease, but a 35,000-fold-higher concentration did not appreciably inhibit a panel of 79 proteases, ion channels, transporters, and cell surface receptors. Subnanomolar biochemical potency was maintained against NS3/4A derived from HCV genotypes 4, 5, and 6, while single-digit nanomolar potency was observed against NS3/4A from genotypes 2b and 3a. Dilution of a preformed enzyme inhibitor complex indicated ITMN-191 remained bound to and inhibited NS3/4A for more than 5 h after its initial association. In cell-based potency assays, half-maximal reduction of genotype 1b HCV replicon RNA was afforded by 1.8 nM; 45 nM eliminated the HCV replicon from cells. Peginterferon alfa-2a displayed a significant degree of antiviral synergy with ITMN-191 and reduced the concentration of ITMN-191 required for HCV replicon elimination. A 30-mg/kg of body weight oral dose administered to rats or monkeys yielded liver concentrations 12 h after dosing that exceeded the ITMN-191 concentration required to eliminate replicon RNA from cells. These preclinical characteristics compare favorably to those of other inhibitors of NS3/4A in clinical development and therefore support the clinical investigation of ITMN-191 for the treatment of chronic hepatitis C.

Neuromuscular complications of statins

Statins, 3-hydroxy-3-methlglutaryl coenzyme A reductase inhibitors, are commonly prescribed for patients who have hyperlipidemia. Statins were first approved in 1987. Statin therapy is well documented to reduce serum low-density lipoprotein levels, incidence of cardiovascular events, and mortality. Although statin therapy is well tolerated, serious adverse affects have been reported, including neuromuscular and hepatic complications. Myopathy is particularly concerning because of the potential for rhabdomyolysis and death. Recently, peripheral neuropathy also has been identified as a possible complication. The incidence of neuromuscular complications is expected to increase with the increased number of people using statin therapy. Clinicians should be aware of the potential neuromuscular complications. This article reviews epidemiology, possible mechanisms, risk factors, and management of statin-associated neuromuscular complications.

Simvastatin induced rhabdomyolysis and an important clinical link with hypothyroidism

An 85-year-old woman with renal impairment and hypothyroidism was commenced on high dose simvastatin (80 mg) for better lipid control. Shortly after this she developed severe muscular weakness and laboratory evidence of rhabdomyolysis. Despite having hypothyroidism controlled for years with L-thyroxine (100 mcg), her biochemistry now reflected a hypothyroid state with inadequate thyroid replacement. On discontinuing her simvastatin to treat her rhabdomyolysis, the patient's TSH level decreased to normal within 4 weeks without any change in L-thyroxine dosage. To our knowledge this is only the second case reported in the literature of a rare but important interaction between simvastatin and L-thyroxine and the first case reported with associated rhabdomyolysis.

Influence of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on ubiquinone levels in rat skeletal muscle and heart: relationship to cytotoxicity and inhibitory activity for cholesterol synthesis in human skeletal muscle cells

Although statins are prescribed as relatively safe and effective drugs for hypercholesterolemic patients, it has been reported that a significant side effect, myopathy, occurs infrequently during medication. Moreover, because statins decrease cardiac ubiquinone levels, the risk of cardiac dysfunction has been suggested. This study sought to evaluate and compare the cytotoxicity of statins (cerivastatin, pitavastatin, fluvastatin, simvastatin, atorvastatin and pravastatin) in cultured human skeletal muscle cells (HSkMCs) and the effects on ubiquinone levels in statin-treated rat skeletal muscle and heart. Cerivastatin, the most potent inhibitor of HMG-CoA reductase, showed the strongest cytotoxicity (over 10-fold) among the statins examined, while the effects of the others were in a similar range. In rat experiments, neither pitavastatin nor cerivastatin decreased ubiquinone levels in skeletal muscle, but both dose-dependently lowered ubiquinone levels in the heart. As the rates of reduction by pitavastatin (9.6% at 30 mg/kg) and cerivastatin (9.7% at 0.3 mg/kg) were almost equal, it was estimated that cerivastatin reduced ubiquinone levels in the rat heart approximately 100-fold more strongly than pitavastatin, based on the effective doses. We found that cerivastatin showed the most potent cytotoxicity in HSkMCs and strongly lowered ubiquinone levels in the rat heart.

Fluvastatin and Atorvastatin Affect Calcium Homeostasis of Rat Skeletal Muscle Fibers in Vivo and in Vitro by Impairing the Sarcoplasmic Reticulum/Mitochondria Ca2+-Release System

The mechanism by which the 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins) induce skeletal muscle injury is still under debate. By using fura-2 cytofluorimetry on intact extensor digitorum longus muscle fibers, here we provided the first evidence that 2 months in vivo chronic treatment of rats with fluvastatin (5 and 20 mg kg-1) and atorvastatin (5 and 10 mg kg-1) caused an alteration of calcium homeostasis. All treated animals showed a significant increase of resting cytosolic calcium [Ca2+]i, up to 60% with the higher fluvastatin dose and up to 20% with the other treatments. The [Ca2+]i rise induced by statin administration was not due to an increase of sarcolemmal permeability to calcium. Furthermore, the treatments reduced caffeine responsiveness. In vitro application of fluvastatin caused changes of [Ca2+]i, resembling the effect obtained after the in vivo administration. Indeed, fluvastatin produced a shift of mechanical threshold for contraction toward negative potentials and an increase of resting [Ca2+]i. By using ruthenium red and cyclosporine A, we determined the sequence of the statin-induced Ca2+ release mechanism. Mitochondria appeared as the cellular structure responsible for the earlier event leading to a subsequent large sarcoplasmic reticulum Ca2+ release. In conclusion, we suggest that calcium homeostasis alteration may be a crucial event for myotoxicity induced by this widely used class of hypolipidemic drugs.

Dose-Dependent Effects of Docosahexaenoic Acid Supplementation on Blood Lipids in Statin-Treated Hyperlipidaemic Subjects

The objective of the study was to evaluate potential benefits of docosahexaenoic acid (DHA) rich fish oil supplementation as an adjunct to statin therapy for hyperlipidaemia. A total of 45 hyperlipidaemic patients on stable statin therapy with persistent elevation of plasma triglycerides (averaging 2.2 mmol/L) were randomised to take 4 g/day (n = 15) or 8 g/day (n = 15) of tuna oil or olive oil (placebo, n = 15) for 6 months. Plasma lipids, blood pressure and arterial compliance were assessed initially and after 3 and 6 months in 40 subjects who completed the trial. Plasma triglycerides were reduced 27% by 8 g/day DHA-rich fish oil (P < 0.05) but not by 4 g/day when compared with the placebo and this reduction was achieved by 3 months and was sustained at 6 months. Even though total cholesterol was already well controlled by the statin treatment (mean initial level 4.5 mmol/L), there was a further dose-dependent reduction with fish oil supplementation (r = -0.344, P < 0.05). The extent of total cholesterol reduction correlated (r = -0.44) with the initial total cholesterol levels (P < 0.005). In the subset with initial plasma cholesterol above 3.8 mmol/L, plasma very low density lipoprotein (VLDL), intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) were isolated and assayed for cholesterol and apolipoprotein B (apoB) at the commencement of the trial and at 3 months of intervention. Fish oil tended to lower cholesterol and apoB in VLDL and raise both in LDL. There were no changes in IDL cholesterol, IDL apoB and high-density lipoprotein cholesterol. The results demonstrate that DHA-rich fish oil supplementation (2.16 g DHA/day) can improve plasma lipids in a dose-dependent manner in patients taking statins and these changes were achieved by 3 months. Fish oil in addition to statin therapy may be preferable to drug combinations for the treatment of combined hyperlipidaemia.

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.

Statin safety: an assessment using an administrative claims database

The large administrative databases of health plans contain information on drug-related medical adverse events (AE) and constitute an increasingly powerful tool for the assessment of drug safety. We conducted a retrospective observational study using an administrative managed care claims database covering 9 million members from diverse regions of the United States. Patients aged >or=18 years who received >or=2 prescriptions for lipid-lowering drugs between July 1, 2000 and December 1, 2004 were included in the study. Hospitalizations with diagnosis codes (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9]) related to muscle, kidney, and liver were determined for patients exposed to 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins), fibrates, extended-release niacin, cholesterol absorption inhibitors, or statin combination therapy. A total of 473,343 patients contributed 490,988 person-years of monotherapy and 11,624 person-years of combination dyslipidemia therapy. Rates of hospitalization due to AEs in patients on monotherapy with currently available statins were similar, whereas the incidence of hospitalization for muscle disorders increased 6.7-fold with cerivastatin therapy. Patients who received a lipid-lowering medication with a concomitant cytochrome P450 3A4 (CYP3A4) inhibitor had a 6-fold increased rate of muscle disorders, including rhabdomyolysis. Hypertension was associated with a 5-fold increase in both muscle and renal events, whereas patients with diabetes mellitus had a 2.5-fold increased risk of renal events. No hospitalized cases of the index AEs were observed in study subjects during the 6-month period before initiation of the lipid-lowering drug. Statin monotherapy as currently prescribed is generally well tolerated and safe.

Statin-associated myasthenia gravis: report of 4 cases and review of the literature

A few recent individual case reports have suggested that a myasthenic syndrome may be associated with statin treatment, but this association is not well described. We report 4 patients who developed symptoms of myasthenia gravis within 2 weeks of starting treatment with a statin drug. In 1 case the drug appears to have exacerbated underlying myasthenic weakness, whereas in the other 3 cases, de novo antibody formation appears to be most likely. In each case, some degree of recovery followed discontinuation of the statin medication.

Discovery of Potent, Nonsystemic Apical Sodium-Codependent Bile Acid Transporter Inhibitors (Part 2)

In the preceding paper several compounds were reported as potent apical sodium-codependent bile acid transporter (ASBT) inhibitors. Since the primary site for active bile acid reabsorption is via ASBT, which is localized on the luminal surface of the distal ileum, we reasoned that a nonsystemic inhibitor would be desirable to minimize or eliminate potential systemic side effects of an absorbed drug. To ensure bioequivalency and product stability, it was also essential that we identify a nonhygroscopic inhibitor in its most stable crystalline form. A series of benzothiepines were prepared to refine the structure-activity relationship of the substituted phenyl ring at the 5-position of benzothiepine ring and to identify potent, crystalline, nonhygroscopic, and efficacious ASBT inhibitors with low systemic exposure.

Selection of DNA aptamers against rat liver X receptors

Liver X receptors alpha and beta (LXRalpha; LXRbeta) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors. LXRs play an important role in the reverse cholesterol transport and govern the expression of many of the proteins that are indispensable for the regulation of normal cholesterol levels in the body. SELEX, an in vitro selection technology, was used on a single stranded DNA library harboring a 12 randomized nucleotide sequence in order to isolate aptamers showing affinity for LXRalpha. Enzyme-linked assays and surface plasmon resonance measurements showed that the selected aptamers had strong affinities for LXRalpha with apparent dissociation constants, K(d)s, in nanomolar range. All clones carried CG-repeats, indicating a probability for a similar manner of binding to LXRalpha. Very high cross-reactivities were observed when testing the aptamers with LXRbeta (up to 700%) and RXRalpha (up to 50%). If instead we regard the aptamer sequences as selected against LXRbeta, the cross-reactivities decrease considerably, to 17% for LXRalpha and 7% for RXRalpha. Therefore, in the future we are planning to use the obtained aptamers as binders for LXRbeta.

Aspergillus oryzae produces compounds inhibiting cholesterol biosynthesis downstream of dihydrolanosterol

The formation of cholesterol synthesis inhibiting molecules by five different strains of the koji mold Aspergillus oryzae was studied. After growing these strains on a complex liquid medium we found in crude organic phase extracts and specific fractions there from compounds inhibiting cholesterol synthesis in human hepatic T9A4 cells in vitro at enzyme sites downstream of dihydrolanosterol. This was evidenced by using different radioactively labeled precursors, namely acetate, mevalonate, 24,25-dihydro-[24,25-(3)H2]-lanosterol or [3-(3)H]-lathosterol.

Benefits and risks assessment of simvastatin in familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a frequent inherited monogenic disorder, associated with premature coronary artery disease. Life expectancy of FH patients is reduced by 15 - 30 years unless they are adequately treated with lipid-lowering therapy. Patients with this disorder need long-term drug therapy and the selection of treatment should be strongly based on its long-term safety and tolerability. The introduction of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors has changed the treatment of FH. Simvastatin 40 - 80 mg/day effectively reduces serum low-density lipoprotein cholesterol levels, and also reduces triglycerides with a modest rise in high-density lipoprotein cholesterol levels. Other potentially important effects, such as improvement of endothelial function, reduction of LDL oxidation and vascular inflammation, have been associated with simvastatin therapy in FH. In addition, simvastatin has been shown to abolish the progression, and even facilitate the regression of existing human atherosclerotic lesions. The safety and tolerability of simvastatin is clearly highlighted by the low rate of therapy discontinuation observed in several population-based clinical trials. Asymptomatic elevations in liver transaminase levels and myopathy are uncommon. The efficacy and tolerability of simvastatin at doses up to 80 mg/day are well-established, as well as its cost-effectiveness in the management of FH patients.