Cerivastatin

Synthesis of new N-acryl-1-amino-2-phenylethanol and N-acyl-1-amino-3-aryloxypropanols and evaluation of their antihyperlipidemic, LDL-oxidation and antioxidant activity

As a part of our drug discovery program, we identified an alkaloidal amide i.e. Aegeline (V) isolated from the leaves of Aegle marmelos as a dual acting agent (antihyperlipidemic and antihyperglycemic). In continuation of this program, we synthesized new N-acyl-1-amino-2-alcohols (N-acrylated-1-amino-2-phenylethanol and N-acylated-1-amino-3-aryloxypropanols) via Ritter reaction and screened for their in-vivo antihyperlipdemic activity in Triton induced hyperlipidemia model, LDL-oxidation and antioxidant activity. Compounds 3, 11 and 13 showed good antihyperlipidemic activity, LDL-oxidation as well as antioxidant activity and comparable activity with marketed antidyslipidemic drug.

Antidyslipidemic and antioxidant activity of the constituents isolated from the leaves of Calophyllum inophyllum

In continuation of our drug discovery program on Indian medicinal plants, we isolated bioactive compounds (1-5) from the leaves of Calophyllum inophyllum and evaluated their antidyslipidemic activity in triton induced hyperlipidemia model. The calophyllic acid (1A) and isocalophyllic acid (1B) mixture, canophyllic acid (4) and amentoflavone (5) showed dose dependent lipid lowering activity in in vivo experiments. The compounds 1A+1B mixture and 3 also showed good in vitro antioxidant activity.

Synthesis of heavily substituted 2-aminopyridines by displacement of a 6-methylsulfinyl group

2-Aminopyridines, with a variety of polar 6-substituents, were elaborated by displacement of a methylsulfinyl group from the 6-position of the pyridine ring. The requisite 6-thiomethyl pyridines were synthesized by reaction of 2-(1-phenylethylidene)propanedinitriles with dimethyl N-cyanodithioiminocarbonate.

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

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

Antihyperglycemic and antidyslipidemic agent from Aegle marmelos

The plant Aegle marmelos belongs to the family of Rutaceae. From the leaves of A. marmelos an alkaloidal-amide, Aegeline 2, was isolated and found to have antihyperglycemic activity as evidenced by lowering the blood glucose levels by 12.9% and 16.9% at 5 and 24h, respectively, in sucrose challenged streptozotocin induced diabetic rats (STZ-S) model at the dose of 100mg/kg body weight. Aegeline 2 has also significantly decreased the plasma triglyceride (Tg) levels by 55% (P<0.001), total cholesterol (TC) by 24% (P<0.05), and free fatty acids (FFA) by 24%, accompanied with increase in HDL-C by 28% and HDL-C/TC ratio by 66% in dyslipidemic hamster model at the dose of 50mg/kg body weight. The reasonable mapping of compound 2 to validated pharmacophoric hypothesis and 3D QSAR model with an estimated activity (283nM) suggest that the compound 2 might be a beta(3)-AR agonist.

Cerivastatin, a HMG-CoA reductase inhibitor, reduces plasminogen activator inhibitor-1 (PAI-1) expression in endothelial cells by down-regulation of cellular signaling and the inhibition of PAI-1 promoter activity

Statins, which competitively inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity and reduce mevalonate synthesis, are believed to exert a plethora of pleiotropic effects. In this report, molecular mechanisms of the inhibitory effect on plasminogen activator inhibitor type 1 (PAI-1) expression produced by cerivastatin (CRV), the most active compound in this class, were studied using monocultures of human endothelial cell line (EA.hy 926). CRV similar to another statin, lovastatin (LOV), significantly inhibited PAI-1 expression and its release from endothelial cells, nonstimulated and stimulated with TNF-alpha. The inhibitory effect of CRV could be detected at the level of PAI-1 promoter in EA.hy 926 cells transfected with plasmid p800 LUC containing PAI-1 promoter fragment (+71 to -800), as well as at the level of PAI-1 mRNA. The PAI-1 promoter activity was markedly suppressed in the nonstimulated cells and almost completely inhibited in TNF-alpha-stimulated cells. In addition, CRV at low doses (IC(50) of 4 - 6 microM) significantly inhibited mitogen-activated protein kinases (MAPKs) phosphorylation. The majority of inhibitory effects occurred at significantly lower concentrations for CRV compared to LOV. The mechanism by which CRV inhibits PAI-1 expression appears to be directly associated with geranylgeranylation of some cell proteins, since the inhibitory effect on PAI-1 expression can be reversed by geranylgeranyl-pyrophosphate but not by farnesyl-pyrophosphate.

Data collection in clinical toxicology: are there too many variables?

The evidence base of clinical toxicology suffers in comparison to other clinical disciplines. There is an excess of case reports and case series with little in the way of case control or cohort studies, and very few randomized controlled trials. While randomized controlled trials are rightly regarded as the gold standard for interventional studies, they have limitations that are particularly evident in the practice of clinical toxicology. Properly conducted observational studies using quantitative, epidemiological methods [nonrandomized trials, cohort studies (prospective and retrospective), case control methods] can provide answers that may be impossible to obtain from randomized controlled trials. Development of a strong evidence base is essential for progress in clinical toxicology. Whether that evidence base is derived from randomized controlled trials or observational studies, it is essential to collect data. Important observations can be made from basic clinical data and systematic collection of those data into some form of electronic database has siginificant advantages. A clinical database provides accurate information in the areas of clinical practice, quality assurance (audit), and research. In the area of research, an appropriately designed database can be both a source of hypotheses as well as a vehicle to test them. It can also serve as a repository of research data in subsequent randomized controlled trials.

Rhabdomyolysis associated with cerivastatin: six cases within 3 months at one hospital

Rhabdomyolysis is an uncommon complication associated with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. We observed six cases of cerivastatin-associated rhabdomyolysis: two patients developed acute renal failure requiring hemodialysis, and one patient died. Four of the patients had impaired renal function, and five were prescribed drugs with the potential to interact with cerivastatin. Also, five of the six patients presented with symptoms of rhabdomyolysis 3-4 weeks after starting cerivastatin therapy.

Evaluation of myopathy risk for HMG-CoA reductase inhibitors by urethane infusion method

Purpose of the present study was to evaluate the myopathy risk using a urethane infusion method following oral administration of five kinds of commercial HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase inhibitors (HCRIs), (pravastatin (PV), simvastatin (SV), cerivastatin (CeV), atorvastatin (AV), and fluvastatin (FV)) alone or with coadministration of bezafibrate (BF). The solubility of HCRIs in various solvents was determined as a criterion of the physicochemical property. The plasma creatine phosphokinase (CPK) level as a marker of myopathy in normal rats was screened under urethane infusion after oral administration of HCRI alone or with BF coadministration. Also, renal tissue specimens were prepared and the myoglobin remaining in the tissue was visualized by the labeled avidin-biotin technique. The plasma CPK level in normal rats under urethane infusion following oral administration of five kinds of HCRI increased as the dose of HCRI increased, and coadministration of BF further increased the CPK level for each drug. The risk of myopathy evaluated from the CPK level was ranked as follows: CeV>FV>AV>SV>PV. Myoglobin deposition was observed in the cast of proximal tubules, cytoplasm of distal tubules and collecting ducts of rat kidney extracted from rats treated with HCRIs under urethane infusion. Histopathological findings showed that the extent of myoglobin deposition increased on coadministration of BF with each drug. The correlation was found for myopathy risk evaluated by CPK level using the urethane infusion method and drug lipophilicity, ie., the water/n-octanol partition coefficient except for the case of SV. Histopathological findings for the kidney following HCRI treatment also reflected the CPK level in rats under urethane infusion.

Safety profiles for the HMG-CoA reductase inhibitors: treatment and trust

Hypercholesterolaemia is a chronic condition that often requires life-long treatment, making the safety of lipid-lowering drugs a critical issue. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors ('statins') are commonly used as the pharmacotherapeutic treatment of choice for patients with hypercholesterolaemia. These agents have consistently demonstrated a positive safety and tolerability profile, and are recommended by the US National Cholesterol Education Program guidelines and by the European Joint Task Force for Prevention of Coronary Heart Disease to be used after, or in addition to, a first-line approach with diet. Several large-scale clinical trials have shown HMG-CoA reductase inhibitors to be efficacious and well tolerated, and to be associated with a low rate of treatment withdrawal due to adverse events. These studies included mortality and morbidity end-points, and comprised both primary- and secondary-prevention trials. Hepatic, renal and muscular systems are rarely affected during HMG-CoA reductase inhibitor therapy and the few drug interactions that can occur with concomitantly administered drugs are well documented. There is no conclusive evidence linking HMG-CoA reductase inhibitors to the development of cancer in humans. In long term studies with various HMG-CoA reductase inhibitors, there was no increase in cancer rates compared with placebo. Thus, it can be concluded that HMG-CoA reductase inhibitors are well tolerated, effective treatments for hypercholesterolaemia.

Efficacy and drug interactions of the new HMG-CoA reductase inhibitors cerivastatin and atorvastatin in CsA-treated renal transplant recipients

BACKGROUND

Hyperlipidaemia is an important risk factor for cardiovascular disease in renal transplant recipients. The aim of this study was to test the efficacy and possible drug-drug interactions of the new HMG-CoA reductase inhibitors (statins) atorvastatin and cerivastatin in cyclosporin A (CsA)-treated renal transplant patients. Subjects and methods. Thirty patients with stable graft function and LDL cholesterol of 130 mg/dl were randomly assigned to active treatment groups (10 mg atorvastatin or 0.2 mg cerivastatin), or a control group. CsA blood trough levels were controlled on a weekly basis and adapted if they changed more than 25% from baseline values (100-150 ng/ml). Lipid levels and routine laboratory parameters before and after a treatment period of 3 months were compared.

RESULTS

In the group treated with cerivastatin no significant changes in CsA blood trough levels occurred (CsA 116+/-21 ng/ml vs 110+/-20 ng/ml). In contrast, in the group treated with atorvastatin, four of 10 patients had a rise in CsA blood trough levels of more than 25% within 7-14 days of starting therapy. In the remaining patients no significant changes in CsA drug levels occurred. After therapy with atorvastatin or cerivastatin, total cholesterol, LDL cholesterol, and triglycerides were significantly lower compared with baseline conditions. No changes of CsA or lipoprotein levels were present in the control group.

CONCLUSION

In our study population both statins were very effective in lowering elevated LDL cholesterol levels. Cerivastatin did not influence CsA blood trough levels, whereas atorvastatin increased CsA levels in four of 10 patients. Further research in a larger study is necessary in order to confirm these results and to investigate the possible reasons for this drug interaction.

Clinical pharmacokinetics of cerivastatin

Cerivastatin sodium, a novel statin, is a synthetic, enantiomerically pure, pyridine derivative that effectively reduces serum cholesterol levels at microgram doses. Cerivastatin is readily and completely absorbed from the gastrointestinal tract, with plasma concentrations reaching a peak 2 to 3 hours postadministration followed by a monoexponential decay with an elimination half-life (t1/2beta) of 2 to 3 hours. Cerivastatin pharmacokinetics are linear: maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) are proportional to the dose over the range of 0.05 to 0.8 mg. No accumulation is observed on repeated administration. Cerivastatin interindividual variability is described by coefficients of variation of approximately 30 to 40% for its primary pharmacokinetic parameters AUC, Cmax and t1/2beta. The mean absolute oral bioavailability of cerivastatin is 60% because of presystemic first-pass effects. Its pharmacokinetics are not influenced by concomitant administration of food nor by the time of day at which the dose is given. Age, gender, ethnicity and concurrent disease also have no clinically significant effects. Cerivastatin is highly bound to plasma proteins (>99%). The volume of distribution at steady state of about 0.3 L/kg indicates that the drug penetrates only moderately into tissue; conversely, preclinical studies have shown a high affinity for liver tissue, the target site of action. Cerivastatin is exclusively cleared via metabolism. No unchanged drug is excreted. Cerivastatin is subject to 2 main oxidative biotransformation reactions: demethylation of the benzylic methyl ether moiety leading to the metabolite M-1 [catalysed by cytochrome P450 (CYP) 2C8 and CYP3A4] and stereoselective hydroxylation of one methyl group of the 6-isopropyl substituent leading to the metabolite M-23 (catalysed by CYP2C8). The product of the combined biotransformation reactions is a secondary minor metabolite, M-24, not detectable in plasma. All 3 metabolites are active inhibitors of hydroxymethylglutaryl-coenzyme A reductase with a similar potency to the parent drug. Approximately 70% of the administered dose is excreted as metabolites in the faeces, and 30% in the urine. Metabolism by 2 distinct CYP isoforms renders cerivastatin relatively resistant to interactions arising from inhibition of CYP. If one of the pathways is blocked, cerivastatin can be effectively metabolised by the alternative route. In addition, on the basis of in vitro investigations, there is no evidence for either cerivastatin or its metabolites having any inducing or inhibitory activity on CYP. The apparent lack of any clinically relevant interactions with a variety of drugs commonly used by patients in the target population supports this favourable drug-drug interaction profile.

Statins: effective antiatherosclerotic therapy

BACKGROUND

Statins are the most effective agents currently available for lowering plasma levels of low-density lipoprotein cholesterol (LDL-C) and are the mainstay of therapy for hyperlipidemia. The statins are highly liver-selective, inhibiting 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, a key enzyme in the synthesis of cholesterol. Several large, controlled clinical trials have confirmed significant reductions in rates of coronary heart disease morbidity and death with long-term statin therapy in patients with mild to severe hypercholesterolemia.

METHODS AND RESULTS

This review article is based on a literature search of more than 60 relevant articles from peer-reviewed journals. Search engines included Medline and Embase. In surveying clinical and angiographic evidence, we found that statins appear to reduce the incidence of coronary events by slowing the progression of atherosclerosis and preventing atheromatous lesion formation. We found that the 6 statins currently marketed-atorvastatin, cerivastatin, fluvastatin, lovastatin, pravastatin, and simvastatin-differ in their inhibitory action on the HMG-CoA reductase enzyme.

CONCLUSIONS

The use of more potent statins such as atorvastatin and simvastatin affords greater lowering of LDL-C and triglyceride levels, allowing more patients to achieve target goals. The question of how low LDL-C levels should be lowered will be answered by ongoing clinical trials.

New insights into the pharmacodynamic and pharmacokinetic properties of statins

The beneficial effects of statins are assumed to result from their ability to reduce cholesterol biosynthesis. However, because mevalonic acid is the precursor not only of cholesterol, but also of many nonsteroidal isoprenoid compounds, inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase may result in pleiotropic effects. It has been shown that several statins decrease smooth muscle cell migration and proliferation and that sera from fluvastatin-treated patients interfere with its proliferation. Cholesterol accumulation in macrophages can be inhibited by different statins, while both fluvastatin and simvastatin inhibit secretion of metalloproteinases by human monocyte-derived macrophages. The antiatherosclerotic effects of statins may be achieved by modifying hypercholesterolemia and the arterial wall environment as well. Although statins rarely have severe adverse effects, interactions with other drugs deserve attention. Simvastatin, lovastatin, cerivastatin, and atorvastatin are biotransformed in the liver primarily by cytochrome P450-3A4, and are susceptible to drug interactions when co-administered with potential inhibitors of this enzyme. Indeed, pharmacokinetic interactions (e.g., increased bioavailability), myositis, and rhabdomyolysis have been reported following concurrent use of simvastatin or lovastatin and cyclosporine A, mibefradil, or nefazodone. In contrast, fluvastatin (mainly metabolized by cytochrome P450-2C9) and pravastatin (eliminated by other metabolic routes) are less subject to this interaction. Nevertheless, a 5- to 23-fold increase in pravastatin bioavailability has been reported in the presence of cyclosporine A. In summary, statins may have direct effects on the arterial wall, which may contribute to their antiatherosclerotic actions. Furthermore, some statins may have lower adverse drug interaction potential than others, which is an important determinant of safety during long-term therapy.

The magnitude of decrease in hepatic very low density lipoprotein apolipoprotein B secretion is determined by the extent of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibition in miniature pigs

It has been postulated that the rate of hepatic very low density lipoprotein (VLDL) apolipoprotein (apo) B secretion is dependent upon the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. To test this hypothesis in vivo, apoB kinetic studies were carried out in miniature pigs before and after 21 days treatment with high-dose (10 mg/kg/day), atorvastatin (A) or simvastatin (S) (n = 5). Pigs were fed a diet containing fat (34% of calories) and cholesterol (400 mg/day; 0.1%). Statin treatment decreased plasma total cholesterol [31 (A) vs. 20% (S)] and low density lipoprotein (LDL) cholesterol concentrations [42 (A) vs. 24% (S)]. Significant reductions in plasma total triglyceride (46%) and VLDL triglyceride (50%) concentrations were only observed with (A). Autologous [131I]VLDL, [125I]LDL, and [3H]leucine were injected simultaneously, and apoB kinetic parameters were determined by triple-isotope multicompartmental analysis using SAAM II. Statin treatment decreased the VLDL apoB pool size [49 (A) vs. 24% (S)] and the hepatic VLDL apoB secretion rate [50 (A) vs. 33% (S)], with no change in the fractional catabolic rate (FCR). LDL apoB pool size decreased [39 (A) vs. 26% (S)], due to reductions in both the total LDL apoB production rate [30 (A) vs. 21% (S)] and LDL direct synthesis [32 (A) vs. 23% (S)]. A significant increase in the LDL apoB FCR (15%) was only seen with (A). Neither plasma VLDL nor LDL lipoprotein compositions were significantly altered. Hepatic HMG-CoA reductase was inhibited to a greater extent with (A), when compared with (S), as evidenced by 1) a greater induction in hepatic mRNA abundances for HMG-CoA reductase (105%) and the LDL receptor (40%) (both P < 0.05); and 2) a greater decrease in hepatic free (9%) and esterified cholesterol (25%) (both P < 0.05). We conclude that both (A) and (S) decrease hepatic VLDL apoB secretion, in vivo, but that the magnitude is determined by the extent of HMG-CoA reductase inhibition.

Efficacy and safety of 300 micrograms and 400 micrograms cerivastatin once daily in patients with primary hypercholesterolaemia: a multicentre, randomized, double-blind, placebo-controlled study

This study examined the action of cerivastatin, a new statin, in subjects with primary hypercholesterolaemia. The effects of two oral doses of cerivastatin (400 micrograms/day or 300 micrograms/day) were compared with placebo in 349 patients using a multicentre, randomized, double-blind, placebo-controlled study design. Cerivastatin treatment lasted 8 weeks and produced significant reductions in low density lipoprotein-cholesterol (LDL-C) levels from baseline compared with placebo. The reduction in LDL-C was significantly greater with 400 micrograms than with 300 micrograms cerivastatin. When responder rates were examined, the higher (400 micrograms/day) cerivastatin dose was found to be more effective in producing larger (> 40%) reductions in LDL-C levels. Cerivastatin treatment was well tolerated. Only two withdrawals due to adverse events during active treatment occurred, neither of which was considered to be due to the study medication. In addition, no clinically relevant increases in the levels of creatine phosphokinase and hepatic transaminases (alanine transaminase and aspartate transaminase) compared with placebo were seen in this study. In conclusion, cerivastatin treatment produced a significant lowering of LDL-C levels, with the higher dose providing the greatest benefit.

Primary and secondary prevention of coronary artery disease: a follow-up on clinical controlled trials

Most probably the decennia of the 1990s will be called the 'statin decennia' in the history of coronary heart disease prevention. Statins are effective, both in primary and secondary prevention of coronary heart disease, in middle-aged and older (< 76 years) men and women, in both diabetics and non-diabetics with coronary heart disease. Statins used in secondary prevention of coronary heart disease significantly reduce the risk of stroke. They also reduce daily attacks of myocardial ischemia. Pathogenetic pathways leading to 'biological plausibilities' of the statins favourable effects are multiple, which explains their rapid (less than 1 year) influence on coronary events. Until the results from new event trials become available, fibrates have very few indications as first line drug therapy in dyslipidemia. They should be considered in combined therapy with statins. The scientific evidence with statins is overwhelming and the question is no longer 'who should we treat?' but 'who can society afford to treat?'. Health economics are indeed pivotal in the use of statins and public health authorities have to find answers according to their resources or innovative strategies, including new aspects in dietary advice (the 'Mediterranean diet'?).