Fluvastatin: a review of its pharmacology and use in the management of hypercholesterolaemia

Indole-containing pharmaceuticals: targets, pharmacological activities, and SAR studies

Indole is a prestigious heterocyclic skeleton widely found in both naturally-occurring and biologically-active compounds. Pharmaceutical agents containing an indole skeleton in their framework possess a wide range of pharmacological properties, including antiviral, antitumor, analgesic, and other therapeutic activities, and many indole-containing drugs have been proven to have excellent pharmacokinetic and pharmacological effects. Over the past few decades, the FDA has approved over 40 indole-containing drugs for the treatment of various clinical conditions, and the development of indole-related drugs has attracted significant attention from medicinal chemists. This review aims to provide an overview of all the approved drugs that contain an indole nucleus, focusing on their targets, pharmacological activities, and SAR studies.

Preparation of Amorphous Probucol with Fluvastatin Sodium Salt and Stability Comparison Studies of Co-amorphous Probucol with Fluvastatin Sodium Salt and Atorvastatin Calcium Trihydrate Salt

A co-amorphous state composed of probucol (PC) and fluvastatin sodium salt (FLU) was prepared by spray-drying (SD). We have previously reported that PC and atorvastatin calcium trihydrate salt (ATO) formed a co-amorphous state when prepared by a SD method and that the solubility of PC and the amorphous stability were improved by the preparation of the co-amorphous state. In the present study, the physicochemical properties, including the amorphous stability of the prepared co-amorphous state, were characterized. Powder X-ray diffraction measurement results suggested that PC and FLU formed a co-amorphous state and that a higher percentage of PC was dissolved from the PC-FLU co-amorphous state than from the PC-ATO co-amorphous state. The results are attributed to FLU exhibiting greater solubility and wettability than ATO, which is supported by the results of solubility tests and contact-angle measurements. The stability of the amorphous state of PC is higher in the co-amorphous state with ATO than in that with FLU. This difference is attributed to differences in the molecular interaction modes between PC-FLU and PC-ATO. Therefore, the selection of high-wettability molecules as a co-former for the co-amorphous state enhances its water solubility. The present study also indicates that molecular interactions enhance the stability of the co-amorphous state.

Diversity of Solid Forms Promoted by Ball Milling: Characterization and Intrinsic Dissolution Studies of Pioglitazone Hydrochloride and Fluvastatin Sodium Drug-Drug Systems

Coamorphous salt in a 1:1 ratio prepared by ball milling from Fluvastatin sodium (FLV) and Pioglitazone hydrochloride (PGZ·HCl) can be selectively formed by neat grinding (NG). Furthermore, the salt-cocrystal continuum was preferably formed by employing liquid-assisted grinding (LAG) using ethanol (EtOH). Attempts to prepare the coamorphous salt starting from the salt-cocrystal continuum by NG were unsuccessful. Interestingly, through ball milling by NG or LAG, a great diversity of solid forms (PGZ·HCl-FLV 1:1) could be accessed: NG and hexane (coamorphous); ethyl acetate (physical mixture); EtOH (salt-cocrystal continuum); and water (which presents two T_g, indicating immiscibility of the components). An exploration was performed at different drug-to-drug ratios by NG. By differential scanning calorimetry (DSC), the presence of two endothermic events was observed in this screening: incongruous melting point (solidus) and excess of one of the components (liquidus), except in the 1:1 solid form. From these results, eutectic behavior was observed. Through the construction of a binary phase diagram, it was determined that the 1:1 molar ratio gives rise to the formation of the most stable coamorphous composition. Dissolution profile studies of these solid forms were carried out, specifically on pure FLV and the solid forms of PGZ⋅HCl-FLV (1:2; 1:4; and 1:6), together with the coamorphous 1:1 salt. By itself, pure FLV presented the highest K_int (13.6270 ± 0.8127 mg/cm²⋅min). On the other hand, the coamorphous 1:1 showed a very low K_int (0.0220 ± 0.0014 mg/cm²·min), indicating very fast recrystallization by the FLV, which avoids observing a sudden release of this drug in the solution. This same behavior was observed in the eutectic composition 1:2. In the other solid forms, the value of K_int increases along with the %w of FLV. From the mechanochemical point of view, ball milling by NG or LAG became an important synthetic tool since it allows obtaining a great variety of solid forms to explore the solid-state reactivity of the drug-drug solid-form PGZ HCl-FLV.

Recent progress in biologically active indole hybrids: a mini review

The indole moiety is one of the most widespread heterocycles found in both natural products and biological systems. Indoles have important biological activities including anticancer, antioxidant, anti-inflammatory, antifungal, anticholinesterase, and antibacterial properties. Scientists are therefore interested in the synthesis of biologically active indole-based hybrids such as indole-coumarin, indole-chalcone, indole-isatin, indole-pyrimidine and so on, with the aim of improving activity, selectivity, and mitigating side effects. This review will discuss the newly synthesized indole-based hybrids along with their biological activity which will be useful in drug discovery and development.

Progress of Statin Therapy in the Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease (ILD) characterized by the proliferation of fibroblasts and aberrant accumulation of extracellular matrix. These changes are accompanied by structural destruction of the lung tissue and the progressive decline of pulmonary function. In the past few decades, researchers have investigated the pathogenesis of IPF and sought a therapeutic approach for its treatment. Some studies have shown that the occurrence of IPF is related to pulmonary inflammatory injury; however, its specific etiology and pathogenesis remain unknown, and no effective treatment, with the exception of lung transplantation, has been identified yet. Several basic science and clinical studies in recent years have shown that statins, the traditional lipid-lowering drugs, exert significant antifibrotic effects, which can delay the progression of IPF and impairment of pulmonary function. This article is aimed at summarizing the current understanding of the pathogenesis of IPF, the progress of research on the use of statins in IPF models and clinical trials, and its main molecular targets.

Three Musketeers for Lowering Cholesterol: Statins, Ezetimibe and Evolocumab

Coronary heart disease (CHD) is closely related to hypercholesterolemia, and lowering serum cholesterol is currently the most important strategy in reducing CHD. In humans, the serum cholesterol level is determined mainly by three metabolic pathways, namely, dietary cholesterol intake, cholesterol synthesis, and cholesterol degradation in vivo. An intervention that targets the key molecules in the three pathways is an important strategy in lowering serum lipids. Statins inhibit 3-hydroxyl-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) to reduce low-density lipoprotein (LDL) by about 20% to 45%. However, up to 15% of patients cannot tolerate the potential side effects of high statin dosages, and several patients also still do not reach their optimal LDL goals after being treated with statins. Ezetimibe inhibits cholesterol absorption by targeting the Niemann-Pick C1-like 1 protein (NPC1L1), which is related to cholesterol absorption in the intestines. Ezetimibe lowers LDL by about 18% when used alone and by an additional 25% when combined with statin therapy. The proprotein convertase subtilisin/kexin type 9 (PCSK9) increases hepatic LDLR degradation, thereby reducing the liver's ability to remove LDL, which can lead to hypercholesterolemia. Evolocumab, which is a PCSK9 monoclonal antibody, can reduce LDL from baseline by 53% to 56%. The three drugs exert lipid-lowering effects by regulating the three key pathways in lipid metabolism. Combining any with the two other drugs on the basis of statin treatment has improved the lipid-lowering effect. Whether the combination of the three musketeers will reduce the side effects of monotherapy and achieve the lipid-lowering effect should be studied further in the future.

Design and application of intramolecular vinylogous Michael reaction for the construction of 2-alkenyl indoles

A base-mediated transformation based on a designed intramolecular vinylogous Michael addition (intra-VMA) is presented to access 3-substituted 2-alkenyl indole derivatives. The reaction represents the first example of the intra-VMA for the construction of indoles. A one-pot N-allylation of ortho-tosylamidocinnamates/congeners with γ-bromocrotonates followed by intra-VMA has been described to provide access to a diverse range of 2-alkenyl indole derivatives in reasonable to high yields. The synthetic value of the developed intra-VMA has been demonstrated by gram-scale synthesis of a representative indole derivative and also by the formal synthesis of MK-7246: a Merck's clinical CRTH2 antagonist.

Chemistry of 3-hydroxy-2-aryl acrylate: syntheses, mechanisms, and applications

3-Hydroxy-2-aryl acrylate is important scaffold which is widely used for the synthesis of pharmacologically active compounds. This review summarises the synthetic methods of the 3-hydroxy-2-aryl acrylate including mechanisms and applications.

Central composite designed solid dispersion for dissolution enhancement of fluvastatin sodium by kneading technique

Aim: This research is focused on enhancing aqueous solubility and dissolution of fluvastatin sodium (FSS) through solid dispersion (FSS-SD) production using polyethylene glycol 6000 and polyvinyl pyrollidone K-30 by kneading technique. Methodology & results: Central composite design explored the influence of polyethylene glycol 6000 and polyvinyl pyrollidone K-30 on T_50% and Q90. The aqueous saturation solubility of FSS (8.7 ± 1.12 μg/ml) was amplified 20-fold in FSS-SD (179 ± 4.16 μg/ml). Cumulative drug release from FSS and optimized FSS-SD were 27.49 and 87.4% within 90 min, respectively. Conclusion: FSS-SD production using kneading technique offers great prospective in maximizing FSS's solubility and dissolution.

Fluvastatin Inhibits HMG-CoA Reductase and Prevents Non-Small Cell Lung Carcinogenesis

Lung cancer is the leading cause of cancer-related death worldwide. However, promising agents for lung cancer prevention are still very limited. Identification of preventive targets and novel effective preventive agents is urgently needed for clinical applications. In this study, we found that fluvastatin targeted 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGCR), which a rate-limiting enzyme in the mevalonate pathway, and inhibited non-small cell lung cancer (NSCLC) tumorigenesis. Initially, we demonstrated that HMGCR is overexpressed in human lung adenocarcinoma tissues compared with normal tissues. Knockdown of HMGCR in NSCLC cells attenuated growth and induced apoptosis in vitro and in vivo Furthermore, we found that fluvastatin, an inhibitor of HMGCR, suppressed NSCLC cell growth and induced apoptosis. Intriguingly, fluvastastin functions by inhibiting the HMGCR-driven Braf/MEK/ERK1/2 and Akt signaling pathways. Notably, fluvastatin attenuated tumor growth in 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis and in a patient-derived xenograft lung tumor model. Overall, our findings suggest that fluvastatin might be promising chemopreventive or potential therapeutic drug against NSCLC tumorigenesis, providing hope for rapid clinical translation.

Effects of Fluvastatin on the Pharmacokinetics of Repaglinide: Possible Role of CYP3A4 and P-glycoprotein Inhibition by Fluvastatin

The purpose of this study was to investigate the effects of fluvastatin on the pharmacokinetics of repaglinide in rats. The effect of fluvastatin on P-glycoprotein and CYP3A4 activity was evaluated. The pharmacokinetic parameters and blood glucose concentrations were also determined after oral and intravenous administration of repaglinide to rats in the presence and absence of fluvastatin. Fluvastatin inhibited CYP3A4 activity in a concentration-dependent manner with a 50% inhibition concentration(IC₅₀) of 4.1 µM and P-gp activity. Compared to the oral control group, fluvastatin significantly increased the AUC and the peak plasma level of repaglinide by 45.9% and 22.7%, respectively. Fluvastatin significantly decreased the total body clearance (TBC) of repaglinide compared to the control. Fluvastatin also significantly increased the absolute bioavailability (BA) of repaglinide by 46.1% compared to the control group. Moreover, the relative BA of repaglinide was 1.14- to 1.46-fold greater than that of the control. Compared to the i.v. control, fluvastatin significantly increased the AUC_0-∞ of i.v. administered repaglinide. The blood glucose concentrations showed significant differences compared to the oral controls. Fluvastatin enhanced the oral BA of repaglinide, which may be mainly attributable to the inhibition of the CYP3A4-mediated metabolism of repaglinide in the small intestine and/or liver, to the inhibition of the P-gp efflux transporter in the small intestine and/or to the reduction of TBC of repaglinide by fluvastatin. The study has raised the awareness of potential interactions during concomitant use of repaglinide with fluvastatin. Therefore, the concurrent use of repaglinide and fluvastatin may require close monitoring for potential drug interactions.

Effect of Clopidogrel on the Steady-State Pharmacokinetics of Fluvastatin

This study assessed the effects of clopidogrel, a CYP 2C9 inhibitor, on fluvastatin pharmacokinetics in healthy volunteers. The effects of combined clopidogrel-fluvastatin treatment on platelet function were also determined. Subjects received 80 mg fluvastatin (extended-release formulation) alone on days 1 through 9, 80 mg fluvastatin and 300 mg clopidogrel (loading dose) on day 10, and 80 mg fluvastatin and 75 mg clopidogrel (maintenance dose) on days 11 through 19. Compared to treatment with fluvastatin alone, fluvastatin AUC was similar and C(max) increased marginally (15.7%) with concomitant treatment with clopidogrel. Platelet aggregation was inhibited by clopidogrel by 33% two hours after the loading dose and by 47% at steady state, similar to that reported for clopidogrel alone treatment. The authors conclude that coadministration of fluvastatin and clopidogrel has no clinically relevant effect on fluvastatin pharmacokinetics or on platelet inhibition by clopidogrel.

Efeito do exercício físico e estatinas na função muscular em animais com dislipidemia

As estatinas são utilizadas no tratamento das dislipidemias, com grande tolerância; no entanto, vários efeitos colaterais podem surgir, destacando-se miopatia. A prática regular do exercício físico (EF) produz modificações favoráveis no perfil lipídico; entretanto, pode gerar lesões musculares. OBJETIVO: Avaliar o efeito da associação entre exercício físico e estatinas na função muscular, pela análise histológica, em modelo experimental animal com dislipidemia. MÉTODOS: Foram utilizados 80 ratos machos Wistar, distribuídos em oito grupos, incluindo animais submetidos à dieta hipercolesterolêmica (DH), sinvastatina com (G1) e sem (G2) EF; DH e fluvastatina, com (G3) e sem EF (G4); alimentados com ração comercial (RC) na presença (G5) e ausência de (G6) EF; DH submetidos (G7) ou não (G8) a EF. A DH foi administrada por 90 dias, as estatinas e prática de EF em esteira rolante por oito semanas. Os animais foram sacrificados, e o músculo sóleo retirado para análise histológica. Aplicaram-se os testes t de Student pareado e análise multivariada, com nível significante para p < 0,05. RESULTADOS: As principais alterações histológicas encontradas foram fibras de diferentes diâmetros, atróficas, em degeneração, splitting, edema, infiltrado inflamatório. Essas alterações foram observadas em 90% dos animais do grupo G1, 80% do G2, 70% do G3, 30% do G4, 40% do G5 e 30% do G7. Nos grupos G6 e G8 identificaram-se fibras musculares com morfologia preservada. CONCLUSÕES: Na avaliação histológica muscular, a associação entre fluvastatina, sinvastatina e exercício físico acarreta alterações morfológicas com predomínio no uso da sinvastatina, variando de grau leve a grave, no músculo sóleo de ratos, induzidos pelos inibidores da HMG-CoA redutase.

Combined inhibitory effects of celecoxib and fluvastatin on the growth of human hepatocellular carcinoma xenografts in nude mice

This study was designed to investigate the in vivo growth inhibitory effects of celecoxib, a cyclo-oxygenase-2 inhibitor, and fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on the hepatocellular carcinoma (HCC) cell line, BEL-7402. Athymic nude mice implanted with BEL-7402 cells were given celecoxib and fluvastatin, either alone or in combination, and the effect of treatment on tumour growth was evaluated after 6 weeks. The combination of celecoxib and fluvastatin enhanced inhibition of tumour growth, induction of apoptosis, inhibition of tumour cell proliferation, and inhibition of tumour angiogenesis compared with either treatment alone. The combination of celecoxib and fluvastatin also increased levels of the cyclin-dependent kinase inhibitor p21(Waf1/Cip1), decreased levels of p-Akt, myeloid cell leukaemia-1 (Mcl-1) and survivin protein, but had no effect on Akt protein levels in tumours. These results suggest that celecoxib combined with fluvastatin would be more efficacious for the treatment of HCC than either treatment alone and this combination of therapy warrants further research.

Statins: 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors demonstrate anti-atherosclerotic character due to their antioxidant capacity

Atherosclerosis is a chronic inflammatory disease of multiple etiologies. It is associated with the accumulation of oxidized lipids in arterial lesions leading to coronary heart disease. 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (commonly known as statins) are widely used in cardiovascular disease prevention to lower the cholesterol. The antioxidant activity of HMG-CoA reductase inhibitors was studied by lipid peroxidation inhibition assay, DPPH, and hydroxyl radical scavenging-activity methods. The lovastatin (93%) and simvastatin (96%) showed significant action of lipid peroxidation inhibition compared to other HMG-CoA reductase inhibitors. The DPPH radical and hydroxyl radical scavenging activity of simvastatin was 38% and 33%, respectively. The oxidative modification of serum lipid due to reactive oxygen species causes atherosclerosis. This study revealed the importance of lovastatin and simvastatin to prevent oxidative stress-related cardiovascular diseases.

Overexpression of RhoA enhances peritoneal dissemination: RhoA suppression with Lovastatin may be useful for ovarian cancer

Small guanosine triphosphatase RhoA has been known to re-organize cytoskeletons and regulate cell migration. The present authors have previously reported that expression of RhoA is significantly increased in advanced ovarian carcinomas and also in the peritoneal disseminated lesions. The present study investigated whether overexpression of RhoA could alter the progressive behavior of ovarian cancer cells. The effect of various Rho inhibitors on the biological behavior of ovarian cancer cells in vitro and in vivo was also examined. A stable RhoA-transfectant of an ovarian cancer cell line SKOV3 was generated and examined in vitro for alterations of proliferative activity and invasiveness, and also in the nude mice model for peritoneal dissemination. In addition, the effect of a specific Rho inhibitor (C3 exoenzyme), Rho kinase inhibitor (Y27632) and hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (Lovastatin and Pravastatin) were studied in vitro and in vivo. Forced overexpression of RhoA did not alter proliferative activity but significantly increased the invasiveness in vitro, which was suppressed by addition of C3 exoenzyme, Y27834, Lovastatin and Pravastatin. In the nude mice model, the frequency of dissemination and the number of disseminated lesions were significantly increased in the RhoA transfectant than in the control. In addition, oral administration of Lovastatin significantly decreased the number of metastatic sites compared with the control. These findings suggest that upregulation and/or activation of RhoA play an important role in the peritoneal dissemination of ovarian carcinoma, and that Lovastatin might be a candidate for the possible, novel treatment for ovarian carcinoma patients with peritoneal dissemination.

Hmgcr in the corpus allatum controls sexual dimorphism of locomotor activity and body size via the insulin pathway in Drosophila

The insulin signaling pathway has been implicated in several physiological and developmental processes. In mammals, it controls expression of 3-Hydroxy-3-Methylglutaryl CoA Reductase (HMGCR), a key enzyme in cholesterol biosynthesis. In insects, which can not synthesize cholesterol de novo, the HMGCR is implicated in the biosynthesis of juvenile hormone (JH). However, the link between the insulin pathway and JH has not been established. In Drosophila, mutations in the insulin receptor (InR) decrease the rate of JH synthesis. It is also known that both the insulin pathway and JH play a role in the control of sexual dimorphism in locomotor activity. In studies here, to demonstrate that the insulin pathway and HMGCR are functionally linked in Drosophila, we first show that hmgcr mutation also disrupts the sexual dimorphism. Similarly to the InR, HMGCR is expressed in the corpus allatum (ca), which is the gland where JH biosynthesis occurs. Two p[hmgcr-GAL4] lines were therefore generated where RNAi was targeted specifically against the HMGCR or the InR in the ca. We found that RNAi-HMGCR blocked HMGCR expression, while the RNAi-InR blocked both InR and HMGCR expression. Each RNAi caused disruption of sexual dimorphism and produced dwarf flies at specific rearing temperatures. These results provide evidence: (i) that HMGCR expression is controlled by the InR and (ii) that InR and HMGCR specifically in the ca, are involved in the control of body size and sexual dimorphism of locomotor activity.

Combined organ failure with combination antihyperlipidemic treatment: a case of hepatic injury and acute renal failure

OBJECTIVE

To report a case of acute hepatic injury and acute renal failure secondary to rhabdomyolysis associated with fluvastatin-gemfibrozil combination therapy for hyperlipidemia.

CASE SUMMARY

A 56-year-old woman with a history of hyperlipidemia presented with fatigue, weakness in her lower extremities, and red-colored urine. One month prior, she had started combination therapy of fluvastatin 80 mg/day and gemfibrozil 1200 mg/day. On physical examination, she had a serious loss of motor function in the upper and lower extremities. Her laboratory tests revealed severe liver enzyme elevation and abnormal renal function. Abdominal ultrasound did not show hepatic cholestasis, renal parenchymal abnormality, or obstruction.

DISCUSSION

Statins and fibric acid derivatives have complementary effects on mixed hyperlipidemia. However, such combination therapy increases the risk of myopathy, which may result in life-threatening rhabdomyolysis. Several reports have suggested that combination fluvastatin-gemfibrozil therapy is both effective and safe in mixed lipid disorders. In our patient, severe rhabdomyolysis with serious hepatocellular injury was observed one month after the combination antihyperlipidemic therapy was started. Assessment with the Naranjo probability scale determined that an adverse drug reaction was probable. The mechanism of this combined toxicity is difficult to clarify, although in vivo and in vitro studies to date have reported considerable data concerning antihyperlipidemic drug interactions.

CONCLUSIONS

Clinicians should carefully consider the risks and benefits of treating dyslipidemia with fluvastatin-gemfibrozil combination therapy.

Chromosomal damage and atherosclerosis. A protective effect from simvastatin

In uremic patients, the frequency of sister chromatid exchanges appears markedly higher than in the general population. Statins are well known for their pleiotropic effects, which are independent of any reduction in cholesterol circulating levels. The aim of the present study was to determine the effects of exposure to escalating doses of simvastatin on the sister chromatid exchange rate in cultured lymphocytes in order to identify the influence of statin on genomic damage. Peripheral lymphocytic samples for culture were obtained from 25 healthy volunteers, 20 patients with documented carotid atherosclerosis and 30 atherosclerotic patients on maintenance regular acetate-free biofiltration. Hemodialyzed patients had a greater percentage of high frequency cells (50%) than healthy controls (3%) and a significantly higher average number of sister chromatid (9.82+/-2.1 vs. 4.65+/-2.18). The subgroup of hemodialyzed patients with high plaque score values was characterized by significantly greater values for both sister chromatid exchanges rate and high frequency cells percentage. Our findings demonstrate that there is an association between sister chromatid exchanges and high frequency cells rate and atherosclerosis in acetate-free biofiltration patients. In cultures with added simvastatin, high frequency cells percentages and mean sister chromatid exchanges levels were significantly lower than in cultures with an added vehicle alone, the reduction occurring in a dose-dependent fashion, above all in cultures from end stage renal disease patients. The findings, moreover, demonstrate new effects of simvastatin, which appeared to mitigate the expression of genomic damage in our model. However, it is not yet clear whether this effect is due to the prevention of genomic damage or to the potentiation of the DNA repair capacity. Statins may therefore have an anti-atherogenic action partly ascribable to their ability to provide protection against the development of atherosclerotic plaque.

Pharmacokinetic interaction between fluvastatin and diltiazem in rats

The present study aimed to investigate the effect of fluvastatin on the pharmacokinetics of diltiazem in rats. Pharmacokinetic parameters of diltiazem were determined in rats following an oral administration of diltiazem (15 mg/kg) in the presence and absence of fluvastatin (0.6 and 2.0 mg/kg). Compared with the control given diltiazem alone, the C(max) and AUC of diltiazem increased by 30-70% in rats with the concurrent use of fluvastatin, while there was no significant change in T(max) and the plasma half-life (T(1/2)) of diltiazem. Consequently, absolute and relative bioavailability values of diltiazem in the presence of fluvastatin were significantly higher (p<0.05) than those from the control group, implying that fluvastatin could reduce the presystemic extraction of diltiazem. In conclusion, the concurrent use of fluvastatin significantly enhanced the oral exposure of diltiazem in rats.

Anti-oxidative effect of fluvastatin in hyperlipidemic type 2 diabetic patients

An open-label prospective cross-over trial was performed to evaluate the antioxidative effect of fluvastatin in Japanese type 2 diabetics with hyperlipidemia. The study subjects were 10 patients who were on pravastatin (10 mg/day) or simvastatin (5 mg/day). After at least 12 weeks of continuous pravastatin or simvastatin therapy, the drugs were washed out for 12 weeks and replaced with fluvastatin (30 mg/day), then the treatment was continued for another 12 weeks. Total cholesterol and LDL cholesterol were efficiently and comparably reduced by all three statin agents. There were no differences in serum parameters of oxidative stress such as malondialdehyde-modified low-density lipoprotein, thiobarbituric acid-reactive substances, and 8-iso-prostaglandin F2alpha between pravastatin/simvastatin and fluvastatin. However, fluvastatin, but not pravastatin/simvastatin, significantly reduced 3,5,7-cholestatriene in erythrocyte membrane, representing the extent of membrane cholesterol peroxidation. Our data demonstrated that fluvastatin has a unique anti-oxidative effect in patients with type 2 diabetes and hyperlipidemia, compared with other statins.

A review of the lipid-related effects of fluvastatin

BACKGROUND

Statin therapy has been shown to significantly decrease vascular events and overall mortality in primary and secondary prevention trials. This review considers the pharmacology, nonlipid-lowering effects and clinical trial evidence of fluvastatin based on a survey of PubMed entries.

FINDINGS

Recent clinical data show that treatment with fluvastatin is associated with a variety of benefits in different high-risk populations along with a good safety profile. Fluvastatin exerts non-lipid lowering-associated pleiotropic effects in both clinical and experimental studies. Furthermore, an extended-release formulation of fluvastatin with a favourable pharmacokinetic profile is available.

CONCLUSION

Treatment with fluvastatin offers a convenient, safe and evidence-based approach to managing dyslipidaemias and preventing vascular events.

Efficacy and safety of fluvastatin therapy for hypercholesterolemia after heart transplantation

BACKGROUND

Hypercholesterolemia is frequent after heart transplantation. Statins can reduce cholesterol levels but their use in heart transplant patients is complicated by pharmacokinetic interactions with cyclosporin and the risk of serious adverse effects including rhabdomyolysis. Fluvastatin has been used safely to treat hypercholesterolemia in renal transplant patients but there are few data relating to its use after heart transplantation. Therefore, we conducted a randomised blinded placebo controlled trial.

METHODS AND RESULTS

Seventy-nine patients, 3 months to 12 years after heart transplantation with a low density lipoprotein (LDL) cholesterol between 3.5 and 8.0 mmol/l were randomly assigned, in a 2:1 ratio, to receive either fluvastatin 40 mg od (n=52) or matching placebo (n=27). Changes in total cholesterol (TC) in the fluvastatin and placebo groups were -17.0% and +4.5%, respectively, (p<0.001); the corresponding changes in LDL were -20.5% and +4.8% (P<0.001) and in triglycerides -14.5% and +7.1% (p=0.012) at the end of the 1-year study period. Withdrawals were more frequent in the fluvastatin group (23% vs. 11% p=0.24). Two deaths occurred during the study (the rate expected from International Society of Heart Lung Transplantation registry) and appeared to be unrelated to the study medication. There were no episodes of rhabdomyolysis or other serious drug-related side effects.

CONCLUSIONS

Fluvastatin (40 mg/day) was both an effective and a safe treatment for hypercholesterolemia in patients who had undergone heart transplantation more than 3 months previously.

Lovastatin induces apoptosis of anaplastic thyroid cancer cells via inhibition of protein geranylgeranylation and de novo protein synthesis

Lovastatin has been used to treat hypercholesterolemia through blocking the mevalonate biosynthesis pathway. Inhibition of mevalonate synthesis may result in antiproliferation and cell apoptosis. The aim of the present study was to examine the apoptotic effect of lovastatin in human ARO cells and delineate its underlying molecular mechanism. Our results showed that lovastatin dose- and time-dependently induced apoptosis in ARO cells. Pretreatment with cycloheximide dose-dependently suppressed lovastatin-induced apoptosis, suggesting that de novo protein synthesis is required for lovastatin effect on the induction of apoptosis in ARO cells. Treatment of the cells with 50 microM lovastatin induced cytochrome c translocation from mitochondria to cytosol; increases in caspase-2, -3, and -9 activity; and poly (ADP-ribose) polymerase degradation in a time-dependent manner. However, administration of mevalonate or geranylgeraniol, but not farnesol, dose-dependently prevented lovastatin-induced poly (ADP-ribose) polymerase degradation and the occurrence of apoptosis, but treatment with geranylgeranyl transferase inhibitor, GGTI-298, which blocks the geranylgeranylation, induced an increase in the percentage of the apoptotic cells. These data suggest that geranylgeranylation is required for survival of the lovastatin-treated ARO cells. To support this notion, we demonstrate that lovastatin dose-dependently decreased the translocation of RhoA and Rac1, but not Ras, from cytosol to membrane fraction. Moreover, the lovastatin-induced translocation inhibitions in RhoA and Rac1 were prevented by mevalonate and geranylgeraniol but not farnesol. In conclusion, our data suggest that lovastatin induced apoptosis in ARO cells by inhibiting protein geranylgeranylation of the Rho family but not farnesylation of the Ras family.

Protective effect of fluvastatin, an HMG-CoA reductase inhibitor, on the formation of 8-oxo-2'-deoxyguanosine in the nuclear DNA of hamster pancreas after a single administration of N-nitrosobis(2-oxopropyl)amine

We examined whether fluvastatin (FV), a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has antioxidant activity against oxidative DNA damage to hamster pancreas induced by a chemical carcinogen, N-nitrosobis(2-oxopropyl)amine (BOP). Female Syrian golden hamsters were treated with FV by gastric intubation 30 min before BOP administration. Control animals were intubated with saline. Animals were injected subcutaneously with BOP (20 mg/kg body weight) or saline, and sacrificed 1 and 4 h later. The contents of 8-oxo-2'-deoxyguanosine (8-oxodG) in the nuclear DNA and thiobarbituric acid-reacting substances (TBARS) were measured in the pancreas and liver of hamsters. Treatment with more than 0.22 mg/kg body weight FV significantly inhibited the increase in 8-oxodG content induced by BOP treatment. The TBARS contents in pancreas changed similarly by intubation of FV. In the liver, the contents of 8-oxodG and TBARS were not affected by a single administration of BOP. The protective effect of FV was stronger than those of pravastatin and other antioxidants such as Trolox, ascorbic acid and green tea catechin. These results suggest that FV inhibits oxidative damage to DNA and lipids caused by reactive oxygen species formed through the metabolism of chemical carcinogens.

Analytical methods for the quantitative determination of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in biological samples

Published analytical methods for the quantitative determinations of presently available five 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ("statins"), lovastatin, simvastatin, pravastatin, fluvastatin and atorvastatin, are reviewed for therapeutic drug monitoring purpose in patients. Almost all assay reviewed are based on high-performance liquid chromatography or gas chromatography. Some purification steps (liquid-liquid extraction, solid-phase extraction, etc.) have been used before they are submitted to separation by chromatographic procedures and they are detected by various detection methods like UV, fluorescence and mass spectrometry. This review shows that most method may be used quantitative determination of statins in plasma and they are suitable for therapeutic drug monitoring purpose of these drugs.

Fluvastatin attenuates nitrate tolerance in patients with ischemic heart disease complicating hypercholesterolemia

BACKGROUND

Long-term administration of nitrates results in the development of tolerance. Nitrate tolerance is considered to occur in association with oxidative stress, although its underlying mechanisms are multi-factorial. Fluvastatin, a newly developed statin, is considered to have not only a cholesterol-lowering effect but also anti-oxidative properties.

METHODS

In this study, the effect of fluvastatin on nitrate tolerance was investigated in 12 dyslipidemic patients (nine men and three women, aged 63.5+/-6.7 years), who were complicated with ischemic heart disease and had received organic nitrates for a long period.

RESULTS

Four months after fluvastatin therapy, symptoms of angina were significantly reduced. Consumption of sublingual nitrates over 2 weeks significantly decreased (14.4+/-11.2 to 2.3+/-2.5 tablets, P<0.01). In exercise stress testing, exercise duration was significantly prolonged (275+/-73 to 360+/-86 s, P<0.01) and the blood pressure-heart rate products significantly increased (16368+/-2246 to 18381+/-1772, P<0.01). Both the percent change in forearm blood flow with reactive hyperemia (232+/-83 to 282+/-104%, P<0.05) and that after sublingual nitroglycerine (2.5+/-4.7 to 5.8+/-4.7%, P<0.05) were increased. Although the levels of total cholesterol, triglyceride, HDL-cholesterol, and LDL-cholesterol were unchanged, the serum anti-Ox-LDL titer (16.7+/-6.3 to 13.4+/-5.4 AcU/ml, P<0.05) and 8-OHdG level (1.11+/-0.34 to 0.73+/-0.34 ng/ml, P<0.05) decreased.

CONCLUSIONS

Fluvastatin attenuated nitrate tolerance in dyslipidemic patients complicated with ischemic heart disease who had been receiving organic nitrates over long period. The anti-oxidative effect of fluvastatin may attenuate nitrate tolerance.

Beneficial effects of fluvastatin on progressive renal allograft dysfunction

To assess the time-dependent changes in renal function in relation to antioxidant and lipid-lowering effects of fluvastatin in hyperlipidemic renal transplant recipients, 20 patients were treated with fluvastatin 40 mg/d for 12 months, after failure of a dietary program. Plasma malondialdehyde (MDA) levels and lipid profiles were evaluated in relation to serum creatinine and calculated creatinine clearances 18 months before and during the fluvastatin treatment. Mean baseline lipid values were: total cholesterol 318 mg/dL, triglycerides 212 mg/dL, LDL cholesterol 219 mg/dL, HDL cholesterol 58 mg/dL, apolipoprotein A 176 mg/dL, and apolipoprotein B 145 mg/dL. During 12 months of treatment, fluvastatin produced consistent and significant reductions in total and LDL cholesterol (-18.4% and -24.1%), triglycerides (-17.7%), and apolipoprotein B (-22.7%) as well as an increase in HDL cholesterol (12.3%) and apolipoprotein A (9.2%). Plasma MDA levels decreased by 41.8% (from 3.5 +/- 0.3 to 1.8 +/- 0.1 nmol/mL, P =.00002). Creatinine clearance, which had been declining at a rate of 0.32 mL/min/month during the previous 18 months before treatment, progressively improved during treatment, giving a positive slope of the creatinine clearance, which increased by 0.35 mL/min/month, (P =.016; 53.3 +/- 4.2 mL/min vs 49.8 +/- 4.1 mL/min pretreatment). Multiple linear regression analysis revealed that MDA was the parameter most closely associated with the variability in creatinine clearance. In conclusion, renal transplant patients with lipid abnormalities display renoprotective activity of fluvastatin, possibly due to its lipid-lowering and antioxidant effects.

Antioxidative potential of fluvastatin via the inhibition of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity

We previously reported that fluvastatin, a potent 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, a strong lipid lowering drug, exerted an anti-atherosclerotic effect at doses insufficient to lower serum lipids in cholesterol fed rabbits. The evidence demonstrated that the superoxide anions from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase plays a critical role in several steps in the development of atherosclerosis. This study was designed to determine the effects of HMG-CoA reductase inhibitors on the production of the superoxide anions of NADPH oxidase in isolated rat peritoneal neutrophils. Fluvastatin (1-10 microM) decreased phorbol 12-myristate 13-acetate (PMA, 10 nM)-dependent reactive oxygen species (ROS) generation in a concentration-dependent manner. It also (10 microM) decreased PMA-dependent O(2) consumption of the rat neutrophils. These effects were reversed by the addition of mevalonate, a metabolite in the HMG-CoA reductase pathway. Treatment with pravastatin did not show any significant changes. Fluvastatin (10 microM) decreased ROS, such as hydroxyl radicals and superoxide anions generated by the Fenton reaction, and by the xanthine-xanthine oxidase system. Rats were treated with either fluvastatin (5 mg/kg per day, p.o.) or pravastatin (5 mg/kg per day, p.o.) for 1 week. Treatment with fluvastatin decreased the PMA-dependent ROS generation. The fluvastatin induced effect on the PMA-dependent ROS generation was reversed by the combined administration with 40 mg/kg mevalonate per day. The antioxidative effect of fluvastatin was thought to have caused not only the scavenging action of the radicals but also to have inhibited ROS generation by inhibiting the NADPH oxidase activity. This antioxidative potential of fluvastatin via the inhibition of NADPH oxidase activity may be profitable in preventing atherosclerosis.

α-Heterosubstituted Aldehydes in Organic Synthesis. Enantioselective Approaches to New Analogues of Mevinic Acids

Various aldol approaches towards the asymmetric synthesis of the lactone moiety of HMG-CoA-reductase inhibitors are described. Auxiliary controlled as well as catalytic aldol reactions resulted only in modest to low selectivities, whereas 1,2-additions to readily available highly enantiomerically enriched α-heterosubstituted aldehydes yielded δ-hydroxy-β-ketoesters with a high degree of diastereocontrol and in good chemical yields. The novel mevinic acid analogues could then be obtained bysyn-reduction of the addition products.

Antioxidative effects of fluvastatin and its metabolites against DNA damage in streptozotocin-treated mice

Fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, and its metabolites have been reported to protect against oxidative DNA damage in vitro. Streptozotocin (STZ) has drawn attention as a potential source of oxidative stress that induces genotoxicity. In order to elucidate the antioxidative effects of fluvastatin in vivo, we investigated the effects of 7-day treatment with fluvastatin on DNA damage in STZ-treated mice, as well as the effects of the main fluvastatin metabolites (M2, M3 and M4) and other inhibitors of the same enzyme, pravastatin and simvastatin. Protective effects against DNA damage in the liver and kidney from STZ-treated mice were assessed by the single-cell gel electrophoresis assay, and by detecting 8-hydroxy-2'-deoxyguanosine. A single intraperitoneal injection of STZ (150 mg/kg) increased serum levels of glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and blood urea nitrogen (BUN), and also caused DNA damage in the liver and kidney. Fluvastatin and its metabolites prevented the STZ-induced elevation of DNA damage and inhibited the increase in serum levels of AST, ALT and BUN. Fluvastatin and its metabolites showed protective effects against DNA damage as potent as that of the reference antioxidants (ascorbic acid, trolox and probucol) though pravastatin and simvastatin still lacked protective activity. Fluvastatin protected the mice against STZ-induced DNA damage, and may reduce the risk of oxidative stress in vivo.

Pharmacology of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins), including rosuvastatin and pitavastatin

Coronary heart disease (CHD) is the leading cause of morbidity and mortality in the Western world, with hypercholesterolemia as the major risk factor. The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors represent the most efficient drugsfor the treatment of hypercholesterolemia. They lower plasma cholesterol due to the inhibition of endogenous cholesterol synthesis in the liverand subsequent increased expression of low-density lipoprotein (LDL) receptors, resulting in an up-regulated catabolic rate for plasma LDL. The beneficial effect of statins on the incidence of CHD was clearly demonstrated in several large-scale clinical trials. Currently, five statins (atorvastatin, fluvastatin, lovastatin, pravastatin, and simvastatin) are available, and two novel compounds (pitavastatin, rosuvastatin) are undergoing clinical investigation. To point out potential mechanisms leading to increased toxicity and to compare the novel statins with the established ones, this article summarizes their pharmacological data since the prevalence of adverse events can be explained at least in part by their pharmacokinetic differences.

Pharmacokinetic-pharmacodynamic drug interactions with HMG-CoA reductase inhibitors

The HMG-CoA reductase inhibitors (statins) are effective in both the primary and secondary prevention of ischaemic heart disease. As a group, these drugs are well tolerated apart from two uncommon but potentially serious adverse effects: elevation of liver enzymes and skeletal muscle abnormalities, which range from benign myalgias to life-threatening rhabdomyolysis. Adverse effects with statins are frequently associated with drug interactions because of their long-term use in older patients who are likely to be exposed to polypharmacy. The recent withdrawal of cerivastatin as a result of deaths from rhabdomyolysis illustrates the clinical importance of such interactions. Drug interactions involving the statins may have either a pharmacodynamic or pharmacokinetic basis, or both. As these drugs are highly extracted by the liver, displacement interactions are of limited importance. The cytochrome P450 (CYP) enzyme system plays an important part in the metabolism of the statins, leading to clinically relevant interactions with other agents, particularly cyclosporin, erythromycin, itraconazole, ketoconazole and HIV protease inhibitors, that are also metabolised by this enzyme system. An additional complicating feature is that individual statins are metabolised to differing degrees, in some cases producing active metabolites. The CYP3A family metabolises lovastatin, simvastatin, atorvastatin and cerivastatin, whereas CYP2C9 metabolises fluvastatin. Cerivastatin is also metabolised by CYP2C8. Pravastatin is not significantly metabolised by the CYP system. In addition, the statins are substrates for P-glycoprotein, a drug transporter present in the small intestine that may influence their oral bioavailability. In clinical practice, the risk of a serious interaction causing myopathy is enhanced when statin metabolism is markedly inhibited. Thus, rhabdomyolysis has occurred following the coadministration of cyclosporin, a potent CYP3A4 and P-glycoprotein inhibitor, and lovastatin. Itraconazole has been shown to increase exposure to simvastatin and its active metabolite by at least 10-fold. Pharmacodynamically, there is an increased risk of myopathy when statins are coprescribed with fibrates or nicotinic acid. This occurs relatively infrequently, but is particularly associated with the combination of cerivastatin and gemfibrozil. Statins may also alter the concentrations of other drugs, such as warfarin or digoxin, leading to alterations in effect or a requirement for clinical monitoring. Knowledge of the pharmacokinetic properties of the statins should allow the avoidance of the majority of drug interactions. If concurrent therapy with known inhibitors of statin metabolism is necessary, the patient should be monitored for signs and symptoms of myopathy or rhabdomyolysis and the statin should be discontinued if necessary.

The effect of fluvastatin of hyperlipidemia in renal transplant recipients: a prospective, placebo-controlled study

Posttransplant hyperlipidemia is a common complication which may affect long term cardiovascular mortality. In this prospective, placebo-controlled study, 19 renal transplant recipients (11 male 8 female, mean age 31.2 +/- 8.4 years) with good allograft function (serum creatinine <2 mg/dl) more than 6 months after transplantation were included. All the patients had hyperlipidemia (serum cholesterol >230 mg/dl and/or LDL-cholesterol >130 mg/dl) despite dietary interventions. The patients were treated with a triple immunosuppressive regimen. After a 8-week period of placebo plus diet regimen, the patients were put on fluvastatin plus diet for another 8 weeks. The patients were followed for its effect on lipid parameters and side effects. After convertion to fluvastatin, serum cholesterol (263.0 +/- 31.6 vs 223.2 +/- 31.6 mg/dl, p = 0.001), LDL-cholesterol (174.4 +/- 28.3 vs 136.4 +/- 28.5 mg/dl, p = 0.002), Apolipoprotein (Apo) A1 (131.1 +/- 16.9 vs 114.7 +/- 18.4 mg/dl, p = 0.001) and Apo B (109.0 +/- 29.8 vs 97.3 +/- 31.5 mg/dl, p = 0.02) levels decreased significantly. Serum levels of triglycerides, VLDL-cholesterol and HDL-cholesterol levels did not vary under fluvastatin. Serum lipoprotein (a) levels were also unchanged during the whole study period (24.9 +/- 19.4 vs 23.1 +/- 19.8 mg/dl, p > 0.05). We concluded that fluvastatin effectively decreased atherogenic lipoproteins such as serum cholesterol, LDL-cholesterol, Apo B in posttransplant hyperlipidemia, however fluvastatin had no effect on another independent risk factor of atherogenesis, serum lipoprotein (a) levels.

How well tolerated are lipid-lowering drugs?

It has been clearly established that lipid-lowering treatments [such as 3-hydroxyl-3-methylglutamyl coenzyme A reductase inhibitors ('statins') or fibrates] can reduce cardiovascular events, and with one of the statins even total mortality, in high-risk populations. Intervention studies have not included the very old, but it is generally assumed that this patient group would benefit from these treatments to an extent similar to younger patients. Worries about the associations seen in observational studies between low cholesterol levels and cancer, cerebral haemorrhage or mood and behaviour change have been largely overcome by findings from the latest large drug intervention trials, which do not show any increase in these conditions with statin or fibrate treatments. The common adverse effects associated with these drugs are relatively mild and often transient in nature. Potentially more serious adverse effects, which are more clearly related to drug treatment and are probably dose-dependent, include elevations in hepatic transaminase levels and myopathy; however, these effects are uncommon and generally resolve rapidly when treatment is stopped. The risk of myopathy with fibrate treatment is increased in patients with renal impairment, and the risk of myopathy with statin treatment increases with co-administration of drugs that inhibit statin metabolism or transport. Other adverse effects are related to specific drugs, for example, clofibrate is associated with an increased risk of gallstones. Studies in elderly patients have not shown an increased risk of adverse effects with lipid-lowering drugs compared with younger patients, but in clinical practice there may be some increased risk, particularly with regards to drug interactions. Therefore, lipid-lowering drugs should be administered with extra caution to elderly patients.

HMG-CoA reductase inhibitors and the malignant cell: the statin family of drugs as triggers of tumor-specific apoptosis

The statin family of drugs target HMG-CoA reductase, the rate-limiting enzyme of the mevalonate pathway, and have been used successfully in the treatment of hypercholesterolemia for the past 15 years. Experimental evidence suggests this key biochemical pathway holds an important role in the carcinogenic process. Moreover, statin administration in vivo can provide an oncoprotective effect. Indeed, in vitro studies have shown the statins can trigger cells of certain tumor types, such as acute myelogenous leukemia, to undergo apoptosis in a sensitive and specific manner. Mechanistic studies show bcl-2 expression is down-regulated in transformed cells undergoing apoptosis in response to statin exposure. In addition, the apoptotic response is in part due to the depletion of the downstream product geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate or other products of the mevalonate pathway including cholesterol. Clinically, preliminary phase I clinical trials have shown the achievable plasma concentration corresponds to the dose range that can trigger apoptosis of tumor types in vitro. Moreover, little toxicity was evident in vivo even at high concentrations. Clearly, additional clinical trials are warranted to further assess the safety and efficacy of statins as novel and immediately available anti-cancer agents. In this article, the experimental evidence supporting a role for the statin family of drugs to this new application will be reviewed.

Lipid-lowering therapy with fluvastatin inhibits oxidative modification of low density lipoprotein and improves vascular endothelial function in hypercholesterolemic patients

This prospective randomized trial was designed to elucidate clinically the effect of fluvastatin on inhibiting oxidation of the low density lipoprotein (LDL) and improving the vascular endothelial function as well as its lipid-lowering effects, in comparison with pravastatin. Of 64 consecutive dyslipidemic patients, 40 patients, whose level of total cholesterol or LDL-cholesterol maintained the criteria of the hypercholesterolemia in spite of 12-week dietary therapy, were randomly assigned to receive either fluvastatin (n=20) or pravastatin (n=20). We assessed the titer of antibody against oxidized LDL (anti-Ox-LDL) as a biomarker for LDL-oxidation, and the forearm blood flow response during reactive hyperemia by venous occlusion plethysmography, which indicates the endothelium-dependent vasodilator capacity. After the 16-week lipid-lowering therapy, the anti-Ox-LDL titer significantly decreased in the fluvastatin group (P<0.01) but did not change in the pravastatin group. The percent increase in the forearm blood flow at the peak reactive hyperemia from the baseline value (%RH) significantly increased in the fluvastatin group (P<0.001) but did not change in the pravastatin group. The ratio of the %RH after the therapy over the baseline value negatively correlated with that of the anti-Ox-LDL titer (R=0.73, P<0.001) in all patients. Fluvastatin may serve as an ideal drug for reducing the risk of atherosclerosis, not only by its cholesterol-lowering effect but also by its unique effects of inhibiting LDL oxidation and improving the vascular endothelial function.

3-hydroxy-3-methylglutaryl-coenzyme a reductase inhibitors reduce human pancreatic cancer cell invasion and metastasis

BACKGROUND & AIMS

Inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase blocks the mevalonate metabolic pathway, which is necessary for the isoprenylation of a number of small guanosine triphosphatases. We examined the effects of HMG-CoA reductase inhibitors, fluvastatin and lovastatin, on human pancreatic cancer cell invasion in vitro and experimental liver metastasis in vivo.

METHODS

Cell invasion was studied in a modified Boyden chamber assay. The translocation of RhoA was assessed by immunoblotting. Experimental liver metastases were induced in nude mice by intrasplenic inoculation of ASPC-1 human pancreatic cancer cells.

RESULTS

Fluvastatin and lovastatin inhibited the in vitro cancer cell invasion induced by epidermal growth factor (EGF) in a manner sensitive to C3 transferase, a specific inhibitor of Rho. Treatment of ASPC-1 cells with fluvastatin markedly attenuated the EGF-induced translocation of RhoA from the cytosol to the membrane fraction and caused cell rounding. The effects of fluvastatin could be reversed by the addition of all-trans-geranylgeraniol. Administration of fluvastatin to nude mice reduced both metastatic tumor formation in the liver and the growth of established liver metastases at doses recommended for the treatment of hypercholesterolemia in humans.

CONCLUSIONS

HMG-CoA reductase inhibitors can be antimetastatic agents with the potential for useful clinical applications.

Antioxidative effects of fluvastatin and its metabolites against oxidative DNA damage in mammalian cultured cells

We investigated the effects of fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on reactive oxygen species (ROS) and on oxidative DNA damage in vitro, as well as the effects of the main fluvastatin metabolites (M2, M3, and M4) and other inhibitors of the same enzyme, pravastatin and simvastatin. The hydroxyl radical and the superoxide anion scavenging activities of fluvastatin and its metabolites were evaluated using an electron spin resonance spectrometer. Fluvastatin and its metabolites showed superoxide anion scavenging activity in the hypoxanthine-xanthine oxidase system and a strong scavenging effect on the hydroxyl radical produced from Fenton's reaction. Protective effects of fluvastatin on ROS-induced DNA damage of CHL/IU cells were assessed using the single-cell gel electrophoresis assay. CHL/IU cells were exposed to either hydrogen peroxide or t-butylhydroperoxide. Fluvastatin and its metabolites showed protective effects on DNA damage as potent as the reference antioxidants, ascorbic acid, trolox, and probucol, though pravastatin and simvastatin did not exert clear protective effects. These observations suggest that fluvastatin and its metabolites may have radical scavenging activity and the potential to protect cells against oxidative DNA damage. Furthermore, ROS are thought to play a major role in the etiology of a wide variety of diseases such as cellular aging, inflammation, diabetes, and cancer development, so fluvastatin might reduce these risks.

Pharmacokinetics and pharmacodynamics of fluvastatin in heart transplant recipients taking cyclosporine A

During the last decades, transplantation has become an established tool for the treatment of terminal organ failure. Beside immunological factors, hyperlipidemia is the main problem after heart transplantation, causing rapid transplant coronary artery disease (TxCAD) and poor long-term prognosis at the beginning of the transplantation. Heart transplant recipients are now effectively treated with lipid lowering substances, of which HMG-CoA-reductase inhibitors are the most potent. However, treatment with these substances correlates with an increased risk for the development of rhabdomyolysis due to therapy with the immunosuppressive cyclosporine A. Our study monitored the safety and efficacy of treatment with the HMG-CoA reductase inhibitor fluvastatin in heart transplant recipients compared to healthy controls. We investigated 10 patients receiving immunosuppressive therapy consisting of cyclosporine A, prednisone, and azathioprine who had increased concentrations of LDL-cholesterol (LDL-C), and 10 age-matched healthy controls. The patients were treated with 40 mg/day fluvastatin for 4 weeks and 20 mg/day for 4 additional weeks. Control individuals received 40 mg/day fluvastatin for 4 weeks only. Parameters of fluvastatin pharmacokinetics (maximum concentration of the drug (C(max.)), time (t(max.)) to reach C(max.), area under the concentration vs. time curve (AUC(0h-24h)), elimination half-life time (t(1/2))), apparent total body clearance (CL), blood cyclosporine A concentration, plasma lipids, and safety parameters were determined in both study groups at the beginning of the study and after 4 weeks. The latter were determined in the patient group also after 8 and 12 weeks. Treatment with 40 mg/day fluvastatin caused a significant decrease in total cholesterol (patients: 5.47 +/- 1.32 mmol/L vs. 7.30 +/- 1.83 mmol/L; controls: 4.69 +/- 0.64 mmol/L vs. 5.81 +/- 0.72 mmol/L), LDL-C (patients: 3.28 +/- 1.25 mmol/L vs. 5.00 +/- 1.85 mmol/L; controls: 2.58 +/- 0.63 mmol/L vs. 3.50 +/- 0.70 mmol/L), and triglycerides (patients: 1.99 +/- 0.77 mmol/L vs. 2.50 +/- 1.00 mmol/L; controls: 1.24 +/- 0.46 mmol/L vs. 1.72 +/- 0.67 mmol/L) in both study groups, whereas HDL-C was not significantly changed (patients: 1.29 +/- 0.35 mmol/L vs. 1.17 +/- 0.32 mmol/L; controls: 1.55 +/- 0.30 mmol/L vs. 1.53 +/- 0.26 mmol/L). Values of C(max.) and AUC(0h-24h) were higher in the patient group than in the control group (day 1, patients vs. controls, C(max.): 869.4 +/- 604.0 ng/mL vs. 211.9 +/- 113.9 ng/mL; AUC(0h-24h): 1948.8 +/- 1347.9 ng/mL*h vs. 549.4 +/- 247.4 ng/mL*h), whereas the corresponding value of CL was lower in the patient group (33.3 +/- 24.5 L/h vs. 107.9 +/- 95.8 L/h), and the values of t(max.) and t(1/2) showed no differences. In addition, values of C(max.) and AUC(0h-24h) after administration of 40 mg/day fluvastatin for 4 weeks in both groups were slightly higher than at the beginning, whereas the value of CL was slightly lower (day 28, patients vs. controls, C(max.): 1530.4 +/- 960.4 ng/mL vs. 254.7 +/- 199.8 ng/mL; AUC(0h-24h): 2615.3 +/- 1379.4 ng/mL*h vs. 841.8 +/- 421.4 ng/mL*h; CL: day 28, 21.4 +/- 15.3 L/h vs. 61.5 +/- 36.6 L/h). Except for an intermittent increase of creatine kinase, safety parameters showed no increases within the observation period. Our data suggest that fluvastatin effectively lowers plasma concentrations of cholesterol and LDL-C in patients after heart transplantation, however, the metabolism of fluvastatin is affected by concomitant therapy with cyclosporine A. Serum concentrations of fluvastatin should be monitored in cases of concomitant therapy with other substances interfering in the metabolism by competing cytochrome enzymes.

Clinical pharmacokinetics of fluvastatin

Fluvastatin, the first fully synthetic HMG-CoA reductase inhibitor, has been shown to reduce cholesterol in patients with hyperlipidaemia, to prevent subsequent coronary events in patients with established coronary heart disease, and to alter endothelial function and plaque stability in animal models. Fluvastatin is relatively hydrophilic, compared with the semisynthetic HMG-CoA reductase inhibitors, and, therefore, it is extensively absorbed from the gastrointestinal tract. After absorption, it is nearly completely extracted and metabolised in the liver to 2 hydroxylated metabolites and an N-desisopropyl metabolite, which are excreted in the bile. Approximately 95% of a dose is recovered in the faeces, with 60% of a dose recovered as the 3 metabolites. The 6-hydroxy and N-desisopropyl fluvastatin metabolites are exclusively generated by cytochrome P450 (CYP) 2C9 and do not accumulate in the blood. CYP2C9, CYP3A4, CYP2C8 and CYP2D6 form the 5-hydroxy fluvastatin metabolite. Because of its hydrophilic nature and extensive plasma protein binding, fluvastatin has a small volume of distribution with minimal concentrations in extrahepatic tissues. The pharmacokinetics of fluvastatin are not influenced by renal function, due to its extensive metabolism and biliary excretion; limited data in patients with cirrhosis suggest a 30% reduction in oral clearance. Age and gender do not appear to affect the disposition of fluvastatin. CYP3A4 inhibitors (erythromycin, ketoconazole and itraconazole) have no effect on fluvastatin pharmacokinetics, in contrast to other HMG-CoA reductase inhibitors which are primarily metabolised by CYP3A and are subject to potential drug interactions with CYP3A inhibitors. Coadministration of fluvastatin with gastrointestinal agents such as cholestyramine, and gastric acid regulating agents (H2 receptor antagonists and proton pump inhibitors), significantly alters fluvastatin disposition by decreasing and increasing bioavailability, respectively. The nonspecific CYP inducer rifampicin (rifampin) significantly increases fluvastatin oral clearance. In addition to being a CYP2C9 substrate, fluvastatin demonstrates inhibitory effects on this isoenzyme in vitro and in vivo. In human liver microsomes, fluvastatin significantly inhibits the hydroxylation of 2 CYP2C9 substrates, tolbutamide and diclofenac. The oral clearances of the CYP2C9 substrates diclofenac, tolbutamide, glibenclamide (glyburide) and losartan are reduced by 15 to 25% when coadministered with fluvastatin. These alterations have not been shown to be clinically significant. There are inadequate data evaluating the potential interaction of fluvastatin with warfarin and phenytoin, 2 CYP2C9 substrates with a narrow therapeutic index, and caution is recommended when using fluvastatin with these agents. Fluvastatin does not appear to have a significant effect on other CYP isoenzymes or P-glycoprotein-mediated transport in vivo.