Short-term effect of atorvastatin in hypercholesterolaemic renal-transplant patients unresponsive to other statins

Long-term efficacy and safety of cerivastatin 0.8 mg in patients with primary hypercholesterolemia

BACKGROUND

Statins are the agents of choice in reducing elevated plasma low-density lipoprotein cholesterol (LDL-C).

HYPOTHESIS

Cerivastatin 0.8 mg has greater long-term efficacy in reducing LDL-C than pravastatin 40 mg in primary hypercholesterolemia.

METHODS

In this double-blind, parallel-group, 52-week study, patients (n = 1,170) were randomized (4:1:1) to cerivastatin 0.8 mg, cerivastatin 0.4 mg, or placebo daily. After 8 weeks, placebo was switched to pravastatin 40 mg. Patients with insufficient LDL-C lowering after 24 weeks were allowed open-labeled resin therapy.

RESULTS

Cerivastatin 0.8 mg reduced LDL-C versus cerivastatin 0.4 mg (40.8 vs. 33.6%, p <0.0001) or pravastatin 40 mg (31.5%, p<0.0001), and brought 81.8% of all patients, and 54.1% of patients with atherosclerotic disease, to National Cholesterol Education Program (NCEP) goals. Cerivastatin 0.8 mg improved mean total C (-29.0%), triglycerides (-18.3%), and high-density lipoprotein cholesterol (HDL-C) (+9.7%) (all p < or = 0.013 vs. pravastatin 40 mg). Higher baseline triglycerides were associated with greater reductions in triglycerides and elevations in HDL-C with cerivastatin. Cerivastatin was well tolerated; the most commonly reported adverse events were arthralgia, headache, pharyngitis, and rhinitis. Symptomatic creatine kinase > 10x the upper limit of normal (ULN) occurred in 1, 1.5, and 0% of patients receiving cerivastatin 0.8 mg, cerivastatin 0.4 mg, and pravastatin 40 mg, respectively. Repeat hepatic transaminases >3 x ULN occurred in 0.3-0.5, 0.5, and 0% of patients, respectively.

CONCLUSION

In long-term use, cerivastatin 0.8 mg effectively and safely brings the majority of patients to NCEP goal.

Chemistory of Fibrates

Since the description of the synthetic chemical clofibrate in 1962, various derivatives of fibrates with a diversity of chemical structures have been developed. Several of these are used clinically to treat dyslipidemia because they are generally effective in lowering elevated plasma triglycerides and cholesterol. Studies suggest that several biochemical mechanisms underlie fibrate-mediated modulation of lipoprotein and related metabolites. These mechanisms are: 1) induced lipoprotein lipolysis; 2) induced hepatic fatty acid uptake and reduced hepatic triglyceride formation; 3) amplified removal of low density lipoprotein (LDL) particles; 4) reduced neutral lipid (cholesteryl ester and triglyceride) exchange between very low density lipoprotein (VLDL) and high density lipoprotein (HDL) resulting from decreased plasma levels of triglyceride-rich lipoprotein (TRL); and 5) increased HDL production and stimulation of reverse cholesterol transport. Recent studies of structure-based inhibitor design strategy revealed that an independent enzyme, aldose reductase (AR), is a target of fibrate activity, an additional biochemical mechanism. AR has been implicated as a major player in the development of diabetes and diabetic complications because of its ability to catalyze the conversion of glucose to sorbitol. This article discusses various targets of fibrate action, biochemical pathways and commonalities in potential molecular interactions.

Atorvastatin does not affect the pharmacokinetics of cyclosporine in renal transplant recipients

OBJECTIVE

The aim of the present study was to evaluate the possible influence of atorvastatin on the pharmacokinetics of cyclosporine (INN ciclosporin) and its main metabolites, AM1 and AM9, in renal transplant recipients.

METHODS

Whole blood samples from 18 renal transplanted patients on cyclosporine-based immunosuppressive therapy were collected prior to and after 4 weeks of treatment with atorvastatin (10 mg/day) and analysed with regard to both cyclosporine and its main metabolites, AM1 and AM9, using a specific chromatographic method with ultraviolet detection.

RESULTS

On average, AUC(0-12) [area under the whole blood concentration versus time curve in the dosing interval (0-12 h)] of cyclosporine was 5% (-16, 5) (90% confidence interval) lower upon co-administration with atorvastatin. No statistically significant changes in any of the calculated pharmacokinetic variables [AUC(0-12), maximum whole blood concentration (C(max)), whole blood concentration 12 h post dose (C(12)), time to C(max) (t(max)), terminal half-life (t(1/2))] for cyclosporine or the two metabolites, AM1 and AM9, upon atorvastatin treatment were observed. On average, atorvastatin did not affect the ratio between the CYP3A4-mediated metabolite AM9 and cyclosporine, suggesting that atorvastatin does not affect the CYP3A4 metabolism of cyclosporine to any significant extent. However, the influence of atorvastatin on the ratio between AM9 and cyclosporine showed large interindividual variability.

CONCLUSION

The results of this study indicate that atorvastatin does not, on average, affect cyclosporine pharmacokinetics in renal transplant recipients.

Effect of Atorvastatin on Cyclosporine Pharmacokinetics in Liver Transplant Recipients

BACKGROUND

The development of hyperlipidemia after liver transplant is frequently treated with hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) such as atorvastatin. As atorvastatin and the primary immunosuppressant drug, cyclosporine, are metabolized by the same pathway, there is the potential for an interaction.

OBJECTIVE

To determine the effect of atorvastatin on cyclosporine pharmacokinetics in liver transplant recipients.

METHODS

Six stable, long-term adult liver transplant recipients from a single center who developed posttransplant dyslipidemia were recruited to participate in a 14-day, open-label study of atorvastatin 10 mg/d coadministered with standard posttransplant immunosuppression using constant oral doses of cyclosporine and corticosteroids. A 10-point pharmacokinetic profile was performed prior to and on day 14 after commencement of atorvastatin therapy. Cyclosporine concentrations were measured by HPLC-electrospray-tandem mass spectrometry. The AUC was calculated by the linear trapezoidal rule, with other parameters determined by visual inspection.

RESULTS

Atorvastatin coadministration increased the cyclosporine AUC by 9% (range 0–20.6%; 3018 vs 3290 ng•h/mL; p = 0.04). No significant change was evident for other cyclosporine pharmacokinetic parameters. Total cholesterol and low-density lipoprotein cholesterol levels were significantly lower on day 14 than at baseline (p < 0.02). One patient developed a twofold increase in transaminases after 2 weeks of atorvastatin therapy, but no other clinical or biochemical adverse events were recorded.

CONCLUSIONS

Atorvastatin coadministration increases the cyclosporine AUC by approximately 10% in stable liver transplant recipients. This change in systemic exposure to cyclosporine is of questionable clinical significance. Atorvastatin is effective in reducing cholesterol levels in liver transplant recipients.

Potential nontraditional applications of statins

OBJECTIVE

To review the current evidence for use of hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) in nontraditional lipid-related applications, including acute coronary syndromes, peripheral arterial disease, stroke, and renal disease, and to describe ongoing trials evaluating the role of statins in these conditions.

DATA SOURCES

Clinical literature was identified by a MEDLINE search (1990-November 2002) using >/=1 of the following search terms: acute coronary syndrome(s), angina pectoris, atherosclerosis, atorvastatin, clinical trials, diabetes mellitus, end-stage renal disease, fluvastatin, lovastatin, myocardial infarction, peripheral arterial disease, pravastatin, simvastatin, statins, and stroke. Treatment guidelines issued by professional and governmental organizations, such as the American Diabetes Association, American Heart Association, National Cholesterol Education Program, National Kidney Foundation, and National Stroke Foundation, were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Articles identified from the data sources were included if they pertained to the conditions described in the objectives and provided unique information concerning use of statins.

DATA SYNTHESIS

Substantial evidence exists for the use of statins in acute coronary syndromes. Meta-analyses of data from major clinical trials indicate that statins prevent first and recurrent stroke, and large-scale trials are underway to evaluate the efficacy of statins in this setting. Accumulating evidence suggests that statins may be beneficial in reducing the morbidity and mortality associated with peripheral arterial disease and end-stage renal disease, and results from ongoing trials may confirm these benefits. Statins may also have a future role in amelioration of other conditions associated with atherosclerosis, such as diabetes mellitus.

CONCLUSIONS

A large body of evidence supports the evaluation of statins in clinical settings beyond primary and secondary prevention of morbidity and mortality associated with coronary atherosclerosis.

Atorvastatin in dyslipidaemia of the nephrotic syndrome

The combined dyslipidaemia that accompanies the nephrotic syndrome increases the cardiovascular risk and appears to worsen long-term renal function. Our aim was to determine the efficacy and safety of 10 mg atorvastatin in the control of dyslipidaemia in these patients. We carried out a prospective, open, 6 month study of 10 patients with primary or secondary nephrotic syndrome (proteinuria >3.5 g/day, hypoalbuminaemia, oedema and hyperlipidaemia). The changes in lipids and plasma lipoproteins were measured, as well as the safety profile (transaminases, creatine phosphokinase, fibrinogen and antithrombin III activity) and parameters of renal function. The addition of 10 mg atorvastatin daily for 6 months resulted in a 41% reduction in low density lipoprotein (LDL) cholesterol and 31% in triglycerides (both P < 0.05), and a 15% increase in high density lipoprotein (HDL) cholesterol (NS). The drug was well tolerated and there was no change in the safety profile or deterioration in renal function. In fact, the levels of proteinuria fell in all but one patient (6.2 +/- 2.6 vs 4.8 +/- 2.5 g/24 h; P < 0.05). Atorvastatin, at the above dose, and for the time used proved to be a safe drug that effectively reduced dyslipidaemia in patients with nephrotic syndrome.

Atorvastatin: an updated review of its pharmacological properties and use in dyslipidaemia

Atorvastatin is a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. In dosages of 10 to 80 mg/day, atorvastatin reduces levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride and very low-density lipoprotein (VLDL)-cholesterol and increases high-density lipoprotein (HDL)-cholesterol in patients with a wide variety of dyslipidaemias. In large long-term trials in patients with primary hypercholesterolaemia. atorvastatin produced greater reductions in total cholesterol. LDL-cholesterol and triglyceride levels than other HMG-CoA reductase inhibitors. In patients with coronary heart disease (CHD), atorvastatin was more efficacious than lovastatin, pravastatin. fluvastatin and simvastatin in achieving target LDL-cholesterol levels and, in high doses, produced very low LDL-cholesterol levels. Aggressive reduction of serum LDL-cholesterol to 1.9 mmol/L with atorvastatin 80 mg/day for 16 weeks in patients with acute coronary syndromes significantly reduced the incidence of the combined primary end-point events and the secondary end-point of recurrent ischaemic events requiring rehospitalisation in the large. well-designed MIRACL trial. In the AVERT trial, aggressive lipid-lowering therapy with atorvastatin 80 mg/ day for 18 months was at least as effective as coronary angioplasty and usual care in reducing the incidence of ischaemic events in low-risk patients with stable CHD. Long-term studies are currently investigating the effects of atorvastatin on serious cardiac events and mortality in patients with CHD. Pharmacoeconomic studies have shown lipid-lowering with atorvastatin to be cost effective in patients with CHD, men with at least one risk factor for CHD and women with multiple risk factors for CHD. In available studies atorvastatin was more cost effective than most other HMG-CoA reductase inhibitors in achieving target LDL-cholesterol levels. Atorvastatin is well tolerated and adverse events are usually mild and transient. The tolerability profile of atorvastatin is similar to that of other available HMG-CoA reductase inhibitors and to placebo. Elevations of liver transaminases and creatine phosphokinase are infrequent. There have been rare case reports of rhabdomyolysis occurring with concomitant use of atorvastatin and other drugs.

CONCLUSION

Atorvastatin is an appropriate first-line lipid-lowering therapy in numerous groups of patients at low to high risk of CHD. Additionally it has a definite role in treating patients requiring greater decreases in LDL-cholesterol levels. Long-term studies are under way to determine whether achieving very low LDL-cholesterol levels with atorvastatin is likely to show additional benefits on morbidity and mortality in patients with CHD.

Calcineurin inhibitors and post-transplant hyperlipidaemias

Cardiovascular disease is now the leading cause of death in transplant recipients. This is due, in part, to the vulnerability of these patients to a complicated set of conditions including hypertension, diabetes mellitus, and post-transplant hyperlipidaemia (PTHL). PTHL is characterised by persistent elevations in total serum cholesterol, low density lipoprotein cholesterol and triglyceride levels. The causes of PTHL are complex and not fully understood, however several classes of immunosuppressants including the corticosteroids, rapamycins and calcineurin inhibitors, appear to play a role. PTHL has been observed in most studies in which patients received calcineurin inhibitor-based regimens, and has been observed with both tacrolimus and cyclosporin. Comparing these calcineurin inhibitors with regard to the relative incidence or severity of PTHL occurring during treatment is difficult because of the use of higher doses of corticosteroids in cyclosporin-based regimens, as compared with tacrolimus-based regimens. However, current expert opinion suggests that the discrepancies in the relative incidence and severity of PTHL are largely accounted for by this difference in corticosteroid dose. At this point in time, evidence for potential differences is scant and inconclusive. Further study is needed, not only to investigate differences in lipid profile, but also of the relative effects of these immunosuppressants on long term graft function as well as on cardiovascular morbidity and mortality. PTHL can be successfully managed with a combination of dietary management, reduction and, if appropriate, withdrawal of corticosteroids, and the administration of lipid-lowering drugs. With this combination of therapeutic options, the threats to long term health posed by PTHL may be effectively addressed.

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and rhabdomyolysis: considerations in the renal failure patient

An intense debate has developed as to the risk-benefit ratio of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) following the withdrawal of cerivastatin. The development of rhabdomyolysis in cerivastatin-treated patients should have surprised few since myotoxicity is an accepted class effect of statins. What has sprung from the cerivastatin experience though is a concern for other members of this class. Such misgivings, although understandable, are ill advised. Without question, differences exist in the risk of rhabdomyolysis occurrence amongst the various statins. In this regard, pravastatin and fluvastatin are least likely to produce rhabdomyolysis, which, in part, relates to the fact they are not metabolized by the cytochrome P450 3A4 pathway. When muscle damage occurs with statins it is most often the result of a drug-drug interaction rather than a specific adverse response to statin monotherapy. Such drug-drug interactions increase plasma concentrations of a statin and thereby increase the risk of myotoxicity. A growing consensus exists which supports an expanded use of statins in a range of patient groups including the renal failure patient. Polypharmacy and altered drug metabolism increase the risk of myotoxicity, albeit to an ill-defined degree, in this population. Many factors should enter into the choice of a statin in the multiply medicated renal failure patient.