Long Term Experience with Simvastatin

Addition of statins to the standard treatment in patients with cirrhosis: Safety and efficacy

This review summarizes the safety and efficacy of statins in patients with cirrhosis. Due to concerns about the safety of statins in patients with impaired liver function, they have recently been investigated as a potential treatment option in cirrhosis. The most clinically significant adverse event is statin-related myopathy, and this may be related to the high serum statin concentrations in the setting of severely impaired liver function. Rhabdomyolysis is the most serious and potentially life-threatening manifestation. It has recently been demonstrated that the recommended dose of simvastatin in patients with decompensated cirrhosis would be 20 mg/d because higher values, such as 40 mg/d, are associated with many adverse events, especially muscle injury. Likewise, simvastatin should not be administered to patients with Model for End-stage Liver Disease score > 12 and/or Child-Pugh class C because of the high risk of severe muscle injury. Due to the pleiotropic effects, the focus on statins has shifted from being considered harmful to something useful. Through these effects, statins could prevent liver-related morbidity and mortality in cirrhotic patients. Observational studies in large populations of patients with cirrhosis have shown that treatment with statins to decrease high cholesterol levels was associated with a reduced risk of hepatic decompensation, hepatocellular carcinoma development and death. The few randomized controlled trials in patients with cirrhosis and portal hypertension showed that statins lower portal pressure, quite likely through a reduction in hepatic resistance. Another large randomized controlled trial in patients with variceal bleeding showed that simvastatin in addition to standard of care did not prevent rebleeding but improved survival rate. Despite these encouraging outcomes, the quality of the evidence regarding the use of statins is low or very low due to the observational characteristics of most of the studies involved. Therefore, it is advisable to perform further randomized controlled trials on a large series of patients with hard clinical endpoints, using different statin types and varying doses. The objectives would be to prevent liver-related morbidity and mortality rather than treating cirrhosis complications to take additional information that makes it possible to add statins to the standard of care of these patients.

Ezetimibe-Associated Immune Thrombocytopenia

Objective:

To describe a case of immune thrombocytopenia associated with treatment with ezetimibe, a cholesterol absorption inhibitor.

Case Summary:

A 72-year-old man presented with severe thrombocytopenia (platelets 3 × 103/μL) and “wet purpura” 4 weeks after being started on daily therapy using a combination of ezetimibe 10 mg/simvastatin 20 mg. Platelet counts normalized after administration of ezetimibe/ simvastatin was stopped. Nine months later, the patient was restarted on simvastatin because of uncorrected dyslipidemia. Platelet counts remained within the normal range following that rechallenge.

Discussion:

Registry data revealed the possibility of ezetimibe-induced thrombocytopenia, but, as of December 3, 2007, no other case reports on this interaction had been published. This case illustrates the probable occurrence of ezetimibe-induced thrombocytopenia. Platelet counts dropped significantly when ezetimibe therapy was initiated, then resolved upon discontinuation of therapy. Other causes of thrombocytopenia were ruled out, and rechallenge with simvastatin further supports the presence of a causal relationship between thrombocytopenia and ezetimibe. Use of the Naranjo probability scale indicated a probable relationship between thrombocytopenia and ezetimibe therapy. An adverse reaction scale specific for evaluation of drug-induced thrombocytopenia also indicated the probable likelihood of ezetimibe-induced thrombocytopenia. This patient was not rechallenged with ezetimibe due to the highly suggestive timeline present and unnecessary risk for him.

Conclusions:

Ezetimibe-associated thrombocytopenia cannot be ruled out in the patient reported here. Clinicians should be aware of this adverse event.

Benefits and risks assessment of simvastatin in familial hypercholesterolaemia

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

Benefits and risks of simvastatin in patients with familial hypercholesterolaemia

Familial hypercholesterolaemia is a frequent, inherited, monogenic disorder, associated with accelerated development of atherosclerotic disease leading to coronary artery disease. Life expectancy of patients with familial hypercholesterolaemia is reduced by 15-30 years unless they are adequately treated with lipid-lowering therapy. Given the chronic nature of this disease, the selection of a therapeutic approach should be strongly based on its long-term safety and tolerability. The introduction of HMG-CoA reductase inhibitors has revolutionised the treatment of familial hypercholesterolaemia. Simvastatin 40-80 mg/day effectively reduces serum low density lipoprotein (LDL)-cholesterol levels. Furthermore, simvastatin reduces triglycerides and mildly raises high density lipoprotein-cholesterol levels. In addition to the hypolipidaemic effect, other potentially important effects, such as improvement of endothelial function and reduction of LDL oxidation and vascular inflammation, have been associated with HMG-CoA reductase inhibitor therapy. Simvastatin has also been shown to abolish the progression, and even facilitate the regression, of existing human atherosclerotic lesions. The good safety and tolerability profile of simvastatin is clearly highlighted by the low rate of therapy discontinuation observed in several population-based clinical trials. The most common adverse events leading to the discontinuation of therapy are gastrointestinal upset and headache. Asymptomatic elevations in liver transaminase levels and myopathy are uncommon. The overwhelming clinical evidence regarding the long-term use of HMG-CoA reductase inhibitor therapy in patients with familial hypercholesterolaemia together with the long-term safety data (particularly relating to simvastatin) provide support for the use of this drug as a first-line agent when pharmacological treatment is indicated. Early intervention with simvastatin treatment can be successfully implemented with favourable economic benefits.

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.

LDL-cholesterol lowering effect of a generic product of simvastatin compared to simvastatin (Zocor) in Thai hypercholesterolemic subjects -- a randomized crossover study, the first report from Thailand

BACKGROUND

It is commonly agreed that people with a high blood LDL-cholesterol will have a higher risk of coronary artery disease (CAD) than people with low blood LDL-cholesterol. Due to the increasingly high costs of medication in Thailand, the government has set up several measures to combat the problem. One of such strategies is to promote the utilization of locally manufactured drug products, especially those contained in the National Drug List. Simvastatin, an HMG-CoA reductase inhibitor, is listed as an essential drug for the treatment of hypercholesterolemia. Here, we reported the study on the LDL-cholesterol-lowering effect of a generic simvastatin product in comparison with the Zocor, in 43 healthy thai volunteers.

METHOD

The generic product tested was Eucor, locally manufactured by Greater Pharma Ltd., Part, Thailand, and the reference product was Zocor (Merck Sharp & Dohme, USA). The two products were administered as 10-mg single oral doses in a two-period crossover design. After drug administration, serial blood samples were collected every 4 weeks for 16 weeks. The major parameter monitored in this study was blood LDL-cholesterol.

RESULT

After taking the drugs for the first 8 weeks, no statistically significant difference was detected in blood LDL-cholesterol between the first (Zocor-treated) and the second (Eucor-treated) groups. After crossover and taking drugs for further 8 weeks, a similar result was obtained, i.e., no significant difference in blood LDL-cholesterol between the first (Eucor-treated) and the second (Zocor-treated) groups was observed. Upon completion of the 16-week study, there was also no statistically significant difference in the changes of all tested blood parameters between the two products (randomized block ANOVA, N = 37). Only minor side effects, mainly dizziness and nausea, were observed in both products.

CONCLUSION

Our study demonstrated no significant differences in the therapeutic effect and safety between the generic and original simvastatin products.

Benefits of early lipid-lowering intervention in high-risk patients: the lipid intervention strategies for coronary patients study

BACKGROUND

There is controversy about whether lipid-lowering pharmacotherapy should be initiated immediately after an acute coronary event or only after diet and lifestyle changes have proved inadequate.

OBJECTIVE

This study, known as the Lipid Intervention Strategies for Coronary Patients Study, compared the efficacy of immediate versus deferred simvastatin treatment in conjunction with dietary advice about reducing lipid levels in hypercholesterolemic patients with acute coronary syndromes.

METHODS

This randomized, open-label, parallel-group study included 151 hypercholesterolemic (low-density lipoprotein cholesterol [LDL-C] >3.0 mmol/L) men and women aged 35 to 75 years. Within 4 days of diagnosis of acute myocardial infarction (MI) or unstable angina pectoris, all patients received dietary advice from a specially trained nurse. Subsequently, patients were randomized to 2 treatment groups: 1 group received immediate treatment with simvastatin 40 mg/d; patients in the other group received simvastatin 40 mg/d after 3 months only if their LDL-C remained >3.0 mmol/L.

RESULTS

The immediate-simvastatin group (n = 73) and the deferred-simvastatin group (n = 78) were balanced with respect to baseline characteristics. Of the 151 patients, 25% were women, 25% had concomitant hypertension, and 75% had a diagnosis of MI on enrollment. At 3 months, 90% of the patients receiving dietary advice plus immediate simvastatin treatment had achieved the recommended European target LDL-C level of <3.0 mmol/L, compared with 7% of those treated with diet alone. By 6 months, when 92% of the study participants were receiving simvastatin 40 mg/d, the proportion of patients achieving target LDL-C levels was 92% in the group that received immediate simvastatin therapy and 81% in the group that received deferred simvastatin therapy. The reductions in LDL-C (42%-48%) were considered to be clinically comparable between the 2 groups at 12 months.

CONCLUSIONS

On the basis of these results, we concluded that few patients with hypercholesterolemia and acute coronary syndromes reach the recommended European target LDL-C level of <3.0 mmol/L with dietary advice alone. However, early treatment with simvastatin 40 mg/d combined with dietary advice and follow-up at a dedicated outpatient clinic specializing in coronary heart disease resulted in 9 out of 10 patients reaching a recommended target LDL-C level of <3.0 mmol/L. Initiation of simvastatin therapy while a patient is hospitalized may increase the likelihood of the patient's lipid levels being managed according to current recommendations after he or she is discharged.

Effects of atorvastatin, an HMG-CoA reductase inhibitor, on hepatic oxidative metabolism of antipyrine

Possible effects of multiple-dose administration of atorvastatin on the pharmacokinetics of single-dose antipyrine were evaluated in this drug-drug interaction study. Twelve healthy male volunteers received three 200-mg capsules of antipyrine on days 1 and 22, and two 40-mg atorvastatin tablets in the morning on days 8 through 23. Serial blood and urine samples were collected after administration of each antipyrine dose. Plasma was analyzed for antipyrine, and urine samples were analyzed for antipyrine, 4-hydroxyantipyrine, and norantipyrine by validated high-performance liquid chromatography with ultraviolet detection. Overall, antipyrine and atorvastatin doses were well tolerated in healthy volunteers. Mean antipyrine concentrations in plasma after administration of a single, oral dose of antipyrine during coadministration of multiple doses of atorvastatin were nearly superimposible on concentrations after administration of antipyrine alone. Individual and mean parameter values for plasma pharmacokinetics of antipyrine were similar in both treatment periods. Atorvastatin did not significantly alter the fraction of clearance of antipyrine in plasma that occurred by urinary excretion of 4-hydroxyantipyrine and norantipyrine. These results indicate that the recommended highest daily dose of atorvastatin has negligible effects on antipyrine pharmacokinetics and on oxidative pathways responsible for the metabolism of antipyrine.

Biochemical changes and morphological alterations of liver and kidney in hamsters after administration of the HMG-coenzyme A reductase inhibitor, simvastatin: prevention and reversibility by mevalonate

The present study analyses the effects of simvastatin, a specific inhibitor of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA reductase) in male Syrian hamsters fed a standard diet or a diet supplemented with 0.12% cholesterol and 20% coconut oil. In hamsters fed the standard diet, gastric administration of simvastatin (10 mg/kg/day) during 12 days was found to be lethal and to have hepatotoxic and nephrotoxic effects. This toxicity was exacerbated in hamsters fed a hyperlipidaemic diet and was preceded by a progressive anorexia and loss of body weight. Marked elevations in serum aspartate and alanine aminotransferase activities were associated with the organ lesions. All elevated biochemical changes and morphological alterations were prevented or reversed by coadministration of mevalonate, the product of the HMG-CoA reductase. It is suggested that the dramatic effect of simvastatin could result from depletion of a non-sterol metabolite of mevalonate in spite of a lack of protective effects of farnesol and geranylgeraniol in the following study. The toxicity of simvastatin could indeed result from the low basal activity of HMG-CoA reductase in hamster liver coupled with a prolonged inhibition of mevalonate synthesis.

Dual bezafibrate-simvastatin therapy for combined hyperlipidaemia

Statins and fibrates are both effective in the treatment of hyperlipidaemias but are not recommended in combination because episodes of rhabdomyolysis have followed combined lovastatin-gemfibrozil therapy. We assessed treatment with dual bezafibrate-simvastatin therapy in routine clinical practice. In 22 patients, total cholesterol, LDL-cholesterol and triglycerides fell by 20.1% (P < 0.0001), 35.1% (P < 0.001) and 31% (P < 0.05) respectively, and HDL-cholesterol rose by 18.4% (P < 0.05) on combination therapy. The reduction in cholesterol followed the introduction of simvastatin, while the decrease in triglycerides followed treatment with bezafibrate. No patient developed myopathy. We conclude that dual simvastatin-bezafibrate therapy is well tolerated and may reduce triglyceride concentrations, but offers no advantage in cholesterol reduction over treatment with simvastatin alone.