Apoptotic injury in cultured human hepatocytes induced by HMG-CoA reductase inhibitors.

Oishi R.

Department of Pharmacy, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.

Hepatotoxicity is the major complaint during therapy with lipid-lowering agents such as statins, although the cellular mechanisms underlying the statin-induced liver injury are not fully understood. Using cultured human hepatocytes, we investigated the effects of lipophilic as well as hydrophilic statins on the cell viability. Lipophilic statins, including simvastatin, lovastatin, cerivastatin, fluvastatin and atorvastatin, reduced the viability of hepatocytes as assessed by the mitochondrial enzyme activity to reduce WST-8, however, a hydrophilic pravastatin did not cause cell injury. The simvastatin-induced loss of cell viability was attenuated by mevalonate or geranylgeranyl pyrophosphate. Simvastatin-induced DNA fragmentation and increased the number of cells stained with annexin V and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, both of which were reversed by caspase inhibitors such as zDEVD-fmk, zLEHD-fmk and zIETD-fmk. Consistent with these data, the activities of caspase-3, caspase-9 and caspase-8 were elevated by simvastatin. Simvastatin reduced the protein content and mRNA expression for bcl-2 without affecting bax mRNA expression. On the other hand, both lipophilic and hydrophilic statins significantly reduced the content of endogenous cholesterol. These findings suggest that lipophilic statins cause an apoptotic injury in human hepatocytes by stimulating caspase-3 subsequent to the activation of caspase-9 and caspase-8, in which the inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase may be involved.

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Simvastatin reduced ischemic brain injury and perfusion deficits in an embolic model of stroke.

Wang CX.

Stroke Research Laboratory, 533 HMRC, University of Alberta, Edmonton, Canada ABT6G 2S2.

Simvastatin is cholesterol lowering agent and also a modulator of cytokine in the nervous system. The functional significance and neuroprotectiove mechanism of simvastatins in ischemic brain injury is controversial. The purpose of study is to evaluate the effect of simvastatin on ischemic brain injury and to investigate the perfusion capability of brain microvessels in the ischemic injury. This study included two series of experiments. In the first series, we studied if simvastatin is neuroprotective in an embolic model of stroke. The treatments began 2 weeks before middle cerebral artery (MCA) occlusion. Infarct volume was measured at 48 h post stroke. Neurological deficits were assessed at 2 h, 24 h and 48 h post stroke. Results showed that infarct volume in rats which received saline and simvastatin was 32.5 +/- 9.3% (mean +/- SD) and 18.7 +/- 6.5%, respectively. The infarct volume in the simvastatin group was significantly smaller than in the controls (P < 0.002). Treatment with simvastatin also improved neurological deficits and reduced brain edema significantly (P < 0.05). In the second series, we studied if simvastatin can improve microvascular reperfusions after ischemia. Perfusion deficits were detected at 8 h post stroke using Evens blue dye. Neurological deficits were assessed at 2 h and 8 h post stroke. Results showed that perfusion deficit in saline and simvastatin-treated groups were 58.7 +/- 8.7% and 23.4 +/- 7.5%, respectively. The perfusion deficit in simvastatin-treated group was decreased 61% (P < 0.01). These studies thus suggest that simvastatin is a protective agent in ischemic brain injury and this protective effect may be partially due to its action in the improvement of microvascular reperfusion.

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A pharmacoeconomic evaluation of statins in the treatment of hypercholesterolaemia in the primary care setting in Spain.

De Miguel-Clave J.

Zone 6 Primary Care Center, Albacete, Spain. pedrotar saludalia.com

BACKGROUND: Cardiovascular disease is one of the leading causes of death and it has been shown that primary prevention with the HMG-CoA reductase inhibitor (statin) lipid-lowering drugs can reduce cardiovascular events. Acquisition costs vary between statins and this may be an important consideration in the overall cost effectiveness (CE) of different options. OBJECTIVE: To perform a CE study of the main statins used in Japan for primary prevention of cardiovascular disease in patients with high cholesterol levels. STUDY DESIGN: The CE analysis was based on an open-label, prospective, naturalistic, randomised intervention study under usual care conditions in primary care settings in patients with high cholesterol levels (total cholesterol [TC] >240 mg/dL, low-density lipoprotein cholesterol [LDL-C] >160 mg/dL) and one or more cardiovascular risk factors. The analysis was conducted from the perspective of the Spanish National Health System; the year of costing was 2001. PATIENTS: A total of 161 patients (49.7% males), mean age 65 +/- 10.3 years, without evidence of cardiovascular disease were included in the study. Of those, 82.1% were hypertensive, 37.1% had diabetes mellitus and 17.9% were smokers. INTERVENTIONS: Forty-eight patients received oral atorvastatin 10 mg/day, 32 received fluvastatin 40 mg/day, 44 received simvastatin 20 mg/day and 37 patients received pravastatin 20 mg/day for 6 months. MAIN MEASUREMENTS AND RESULTS: After 6 months, the therapeutic goals of LDL-C control, according to the recommendations of the Spanish Society of Arteriosclerosis--Consensus-2000, were reached in 62.5%, 43.8%, 45.5% and 40.5% of patients treated with atorvastatin, fluvastatin, simvastatin and pravastatin, respectively. The average CE ratio, expressed as the cost in euros (euro) per patient achieving the therapeutic goals, was euros 424.3 for atorvastatin, euros 503.5 for fluvastatin, euros 527.0 for simvastatin and euros 683.4 for pravastatin. The incremental CE ratios for atorvastatin versus fluvastatin and simvastatin were euros 238.9 and euros 149.5, respectively, per additional patient reaching therapeutic goals. Atorvastatin, fluvastatin and simvastatin all dominated pravastatin. CONCLUSIONS: All the statins studied have been shown to be effective for reducing both TC and LDL-C levels. In this study, atorvastatin was the most efficient drug, with the best CE ratio (cost per patient reaching therapeutic goals). Atorvastatin was more effective and less costly than pravastatin, and when compared with fluvastatin or simvastatin the additional cost per additional patient achieving therapeutic goals was <euros 250.

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Comparison of ezetimibe plus simvastatin versus simvastatin monotherapy on atherosclerosis progression in familial hypercholesterolemia. Design and rationale of the Ezetimibe and Simvastatin in Hypercholesterolemia Enhances Atherosclerosis Regression (ENHANCE) trial.

Veltri E.

Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands. e.vandongen amc.uva.nl

BACKGROUND: Lipid lowering through statin therapy significantly reduces the risk of cardiovascular events. The ENHANCE study is an international 2-year, randomized, double-blind, controlled trial designed to test the hypothesis that treatment of hypercholesterolemia by use of 2 complementary agents, ezetimibe (a specific cholesterol absorption inhibitor) and simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor), will result in larger beneficial effects on carotid artery intima-media thickness (CA IMT) than simvastatin monotherapy. METHODS: The study will recruit 725 men and women with heterozygous familial hypercholesterolemia. After a placebo washout period, participants are randomized to receive daily administration of either simvastatin 80 mg and ezetimibe 10 mg or simvastatin 80 mg and placebo. The ENHANCE trial uses novel state-of-the-art single-frame digital image acquisition and rigorous quality assurance and control. RESULTS: The primary end point is mean change from baseline to 2 years in CA IMT, using composite measures from the right and left far wall common carotid artery, carotid bulb, and internal carotid artery. Secondary end points include (1) the proportion of participants who exhibit reductions in CA IMT, (2) the change in maximum far wall IMT, (3) the proportion of participants who develop new carotid artery plaques, and (4) the changes in carotid plus common femoral artery IMT. CONCLUSIONS: This study addresses the question of whether a regimen that uses drugs with different mechanisms of action will be of further benefit in terms of atherosclerosis reduction compared to statin monotherapy.

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Cholesterol levels after 3 days of high-dose simvastatin in patients at moderate to high risk for coronary events.

Citkowitz E.

Department of Medicine, Hospital of Saint Raphael, 1450 Chapel Street, New Haven, CT 06511-4417, USA.

BACKGROUND: Elevated levels of low-density lipoprotein cholesterol (LDL-C) impair vascular function by a variety of mechanisms. HMG CoA reductase inhibitors (statins) improve endothelial function by lowering LDL-C and possibly by other "pleiotropic" effects. How rapidly statins can lower LDL-C has not been thoroughly studied. METHODS: We examined the lipid response to 3 days of high-dose simvastatin in a randomized prospective double-blind placebo-controlled crossover study. Twenty-seven subjects at moderate to high risk for coronary heart disease (CHD) received either simvastatin 80 mg/day for 3 days followed by placebo for 3 days or placebo followed by simvastatin. After a washout period of 10 to 14 days, subjects received the opposite treatment. Nonfasting blood lipid levels, including total cholesterol, direct LDL-C, high-density lipoprotein cholesterol (HDL-C), and triglycerides, were obtained before randomization and after each 3-day treatment period. RESULTS: The mean LDL-C level at baseline was 107 mg/dl and decreased 24% in patients receiving simvastatin and 5.6% in patients receiving placebo (P < 0.001). Statistically significant reductions were also achieved in the total cholesterol and cholesterol/HDL-C ratio: 14% and 12%, respectively. Changes in HDL-C and triglyceride levels were not significant. CONCLUSION: Treatment with simvastatin for only 3 days results in a 24% drop in the LDL-C level. As defined by ATPIII, this decrease is comparable to that necessary to lower the LDL-C from one risk level to a lower one and is, therefore, both clinically and statistically significant.

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Effect of alpha-tocopherol and simvastatin on male fertility in hypercholesterolemic rats.

Kamel GM.

Pharmacology Department, Faculty of Veterinary Medicine, Cairo University, P.O. Box 12211, Giza, Egypt.

The effect of alpha-tocopherol, simvastatin and both on male fertility in hypercholesterolemic rats was studied. Induction of hypercholesterolemia was done by feeding rats on a diet containing 1% cholesterol for 30 days. Hypercholesterolemic rats were orally given alpha-tocopherol (3 mg kg(-1) BW) or simvastatin (1 mg kg(-1) BW) or both for 65 days. Fertility index, serum testosterone level, sex organs weight, semen analysis and histopathological examination of testes, seminal vesicles and prostate glands were the parameters used to evaluate the reproductive efficiency of rats. In hypercholesterolemic rats (control +ve), there was a marked decrease in fertility index, testicular weight, sperm cell count, and percentages of sperm motility and viability associated with a significant increase in sperm cell abnormalities. Oral administration of either alpha-tocopherol or simvastatin to hypercholesterolemic rats for 65 days significantly improved the fertility index, testicular weight and semen quality. Concomitant administration of alpha-tocopherol and simvastatin to hypercholesterolemic rats markedly increased fertility index and sperm motility and viability associated with a significant reduction of sperm cell abnormalities. Histopathological examination revealed that testes of hypercholesterolemic rats (control +ve) had degenerated, non-functioning and atrophied seminiferous tubules associated with arrest of spermatogenesis. Oral administration of alpha-tocopherol and simvastatin concomitantly to hypercholesterolemic rats resulted in active mature and full functioning seminiferous tubules. In conclusion, concomitant administration of alpha-tocopherol and simvastatin to hypercholesterolemic male rats improved their reproductive efficiency and produced additional protection against reduced fertility induced by hypercholesterolemia. Copyright 2003 Elsevier Ltd.

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