Statin-induced myopathy: the two faces of Janus

Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) have been shown to be effective at lowering low-density lipoprotein cholesterol and decreasing the risk of coronary heart disease. Although safe and well tolerated by most patients, statins have also been associated with muscle-related adverse events. This article reviews statin-associated myotoxicity to clarify the definitions of muscle-related adverse events and discusses their incidences in major statin trials, case reports, and review articles through January 2006. Milder complaints (ie, myalgia) are reported by approximately 5% to 7% of patients who take statins. More severe myotoxicity, namely rhabdomyolysis, is extremely rare for all statins save cerivastatin, and most recent estimates of its incidence are between 0.44 and 0.54 cases per 10 000 person-years. The mechanism of statin-associated myotoxicity has not been satisfactorily defined and is likely due to multiple factors, including membrane instability, mitochondrial dysfunction, and defects in myocyte duplication.     

Optimizing LDL-C lowering with statins

Clinical studies have demonstrated the efficacy of statins in reducing low-density lipoprotein cholesterol (LDL-C) and lowering coronary heart disease risk. However, many patients receiving statin therapy in clinical practice are not achieving their LDL-C goals. Generally, statins are initiated at starting doses, and doses should be titrated as needed until the goal of therapy is achieved or a second lipid-lowering drug is required; titration is required in the majority of patients who receive less efficacious agents. Most patients receiving statin therapy in clinical practice are maintained on their starting dose, and this frequently results in inadequate control of elevated cholesterol levels. A number of factors may limit dose titration in clinical practice, including the cost of therapy, safety of prescribing statins at high doses and the additional office visits required for evaluations and monitoring. There may be several solutions to this problem. The choice of statin appears to be one of the important factors influencing the success of therapy. Selecting a statin that provides greater LDL-C lowering enables more patients to achieve LDL-C goals, and the majority of patients can be effectively treated with starting doses of the more efficacious statins. Another factor influencing the success of therapy is the willingness to add other drugs to a statin to enhance LDL-C lowering. Choices here include niacin, a bile acid sequestrant, and ezetimibe, a new cholesterol absorption inhibitor. Of these approaches, use of a more efficacious statin is preferred to combination therapy because of cost, safety, effectiveness, and simplicity issues.     

A systematic review and meta‐analysis on the therapeutic equivalence of statins

Background: Statins are the most commonly prescribed agents for hypercholesterolemia because of their efficacy and tolerability. As the number of patients in need of statin therapy continues to increase, information regarding the relative efficacy and safety of statins is required for decision‐making. Objective: This study will use systematic review to compare the efficacy and safety profiles of different statins at different doses and determine the therapeutically equivalent doses of statins to achieve a specific level of low‐density lipoprotein cholesterol (LDL‐C) lowering effect. Methods: Publications of head‐to‐head randomized controlled trials (RCTs) of statins were retrieved from the Oregon state database (1966–2004), MEDLINE (2005‐April of 2006), EMBASE (2005‐April of 2006), and the Cochrane Controlled Trials Registry (up to the first quarter of 2006). The publications were evaluated with predetermined criteria by a reviewer before they were included in the review. The mean change in cholesterol level of each statin was calculated and weighted by number of subjects involved in each RCT. Where possible, meta‐analysis was performed to generate pooled estimates of the cholesterol lowering effect of statins and the difference between statins. Results: Seventy‐five studies reporting RCTs of head‐to‐head comparisons on statins were included. Most studies had similar baseline characteristics, except the rosuvastatin related studies. A daily dose of atorvastatin 10 mg, fluvastatin 80 mg, lovastatin 40–80 mg, and simvastatin 20 mg could decrease LDL‐C by 30–40%, and fluvastatin 40 mg, lovastatin 10–20 mg, pravastatin 20–40 mg, and simvastatin 10 mg could decrease LDL‐C by 20–30%. The only two statins that could reduce LDL‐C more than 40% were rosuvastatin and atorvastatin at a daily dose of 20 mg or higher. Meta‐analysis indicated a statistically significant but clinically minor difference (<7%) between statins in cholesterol lowering effect. Comparisons of coronary heart disease prevention and safety could not be made because of insufficient data. Conclusions: At comparable doses, statins are therapeutically equivalent in reducing LDL‐C.     

Adverse effects of statins

The safety of the hydroxymethyl glutaryl-coenzyme A reductase inhibitors (statins) has been called into question following the recent withdrawal from the market of one of the class, cerivastatin. The withdrawal of cerivastatin highlighted concerns regarding the safety of the entire class. According to data from several large clinical trials, the statins (except cerivastatin) are well tolerated. The most important and clinically relevant adverse effect reported with statins is myopathy. Myopathy is a clinical diagnosis of elevated creatine phosphokinase and/or myalgia along with fatigue. However, the severe from (i.e. statin-associated rhabdomyolysis) is an uncommon syndrome and occurs at a rate of approximately 1/100,000 patients/years. Statin-associated myopathy is related to statin doses, and often to drug/drug interactions. Other clinically relevant adverse effects associated with statin therapy include liver transminases elevation, which is relatively mild and often self-limiting There is no evidence from clinical trials of a significant alteration of ophthalmological function with statins. The issue of statin-induced cancer remains inconclusive. Overall, the statins seem to exhibit a favourable risk/benefit ratio, and this undoubtedly justifies life-long clinical use of statins for cardiovascular prevention.     

Chemical, pharmacokinetic and pharmacodynamic properties of statins: an update

Statins are the treatment of choice for the management of hypercholesterolaemia because of their proven efficacy and safety profile. They also have an increasing role in managing cardiovascular risk in patients with relatively normal levels of plasma cholesterol. Although all statins share a common mechanism of action, they differ in terms of their chemical structures, pharmacokinetic profiles, and lipid-modifying efficacy. The chemical structures of statins govern their water solubility, which in turn influences their absorption, distribution, metabolism and excretion. Lovastatin, pravastatin and simvastatin are derived from fungal metabolites and have elimination half-lives of 1-3 h. Atorvastatin, cerivastatin (withdrawn from clinical use in 2001), fluvastatin, pitavastatin and rosuvastatin are fully synthetic compounds, with elimination half-lives ranging from 1 h for fluvastatin to 19 h for rosuvastatin. Atorvastatin, simvastatin, lovastatin, fluvastatin, cerivastatin and pitavastatin are relatively lipophilic compounds. Lipophilic statins are more susceptible to metabolism by the cytochrome P(450) system, except for pitavastatin, which undergoes limited metabolism via this pathway. Pravastatin and rosuvastatin are relatively hydrophilic and not significantly metabolized by cytochrome P(450) enzymes. All statins are selective for effect in the liver, largely because of efficient first-pass uptake; passive diffusion through hepatocyte cell membranes is primarily responsible for hepatic uptake of lipophilic statins, while hydrophilic agents are taken up by active carrier-mediated processes. Pravastatin and rosuvastatin show greater hepatoselectivity than lipophilic agents, as well as a reduced potential for uptake by peripheral cells. The bioavailability of the statins differs greatly, from 5% for lovastatin and simvastatin to 60% or greater for cerivastatin and pitavastatin. Clinical studies have demonstrated rosuvastatin to be the most effective for reducing low-density lipoprotein cholesterol, followed by atorvastatin, simvastatin and pravastatin. As a class, statins are generally well tolerated and serious adverse events, including muscle toxicity leading to rhabdomyolysis, are rare. Consideration of the differences between the statins helps to provide a rational basis for their use in clinical practice.     

The influence of statin characteristics on their safety and tolerability

The efficacy of the statins for both primary and secondary prevention has now been clearly established in patients across the spectrum of cardiovascular risk. In addition to their primary effect in reducing plasma cholesterol, the statins possess various 'pleiotropic' effects that may contribute to their clinical effectiveness in reducing cardiovascular events, e.g. improvement of endothelial function, reduction of low-density lipoprotein-cholesterol oxidation and stabilisation of atheromatous plaques. Although statins share similar chemical characteristics, they differ significantly in terms of their molecular synthesis, solubility and pharmacokinetic behaviour and metabolism. Side-effects secondary to longterm statin therapy are rare, but rhabdomyolysis may occur when statins are administered together with other drugs that have a direct toxic effect on muscle or which inhibit statin metabolism. Among the various statins, it would appear that fluvastatin has the lowest propensity to interact with other drugs and the least potential to induce myotoxicity.     

A COST-EFFECTIVENESS MODEL OF ALTERNATIVE STATINS TO ACHIEVE TARGET LDL-CHOLESTEROL LEVELS

An economic model was developed to estimate the relative cost-effectiveness of alternative HMG-CoA reductase inhibitors (statins) – atorvastatin, cerivastatin, fluvastatin, pravastatin and simvastatin – to achieve target low-density lipoprotein cholesterol (LDL-C) levels in a population of secondary CHD prevention patients. By using a cholesterol target as the endpoint of interest and a dose titration approach, the model assumes that the statins demonstrate a class effect through cholesterol lowering. The model was used to estimate the proportion of patients achieving target LDL-C levels (<3 mmol/l) under each scenario tested. Total costs and incremental cost-effectiveness relative to no treatment and to the lowest cost option were estimated for each scenario. Total costs were highest for pravastatin and lowest for cerivastatin. Compared with no treatment, the incremental cost per patient treated to target LDL-C varied between £383 (atorvastatin) and £1213 (pravastatin). Incremental cost-effectiveness ratios in comparison with the lowest cost treatment (cerivastatin) were £141 per additional patient achieving target LDL-C with atorvastatin, and £275 with simvastatin. Fluvastatin and pravastatin were both less effective and more expensive than the lowest cost therapy. Although cerivastatin was associated with lowest expected costs, therapy with atorvastatin achieved the lowest cost-effectiveness ratios. Hence atorvastatin would allow the largest number of patients to be treated to target LDL-C within a fixed drug budget. Choosing between drug therapies on the basis of price alone may be misleading if the effectiveness of therapies varies.     

Severe muscle disorders associated with statins: analysis of cases notified in France up to the end of February 2002 and data concerning the risk profile of cerivastatin

BACKGROUND AND METHODS: After the withdrawal of cerivastatin from the market, a survey was performed concerning severe muscular disorders associated with statin treatments that were notified to the French national and pharmaceutical industry pharmacovigilance systems up to February 2002. RESULTS: Among the 238 cases analysed, 69 were related to cerivastatin, 86 to simvastatin, 49 to pravastatin, 23 to atorvastatin and 9 to fluvastatin. The reporting rate was six- to ten-times higher for cerivastatin than for other statins. A major risk factor for rhabdomyolysis with cerivastatin was its association with gemfibrozil. CONCLUSION: Postmarketing surveillance appears to be a major tool for early detection of safety problems with a new drug.     

Ezetimibe in hypercholesterolaemia

Ezetimibe is the first member of a new class of selective cholesterol absorption inhibitors, compounds that effectively block intestinal absorption of dietary and biliary cholesterol, without affecting absorption of fat soluble vitamins or triglycerides. Ezetimibe underwent glucuronidation to a single metabolite and localised at the intestinal wall, where it prevented luminal cholesterol absorption. Pre-clinical studies demonstrated the lipid-lowering and antiatherosclerotic properties of ezetimibe. The efficacy and safety of ezetimibe monotherapy have been determined in phase II/III studies: in phase II studies, the optimal efficacy was reached with ezetimibe 10 mg per day and the pooled efficacy data have shown that ezetimibe 10 mg has a positive effect on the lipoprotein profile with a significant reduction in LDL-cholesterol of 18.5%, an increase in HDL-cholesterol of 3.5% and a trend towards lowering in triglyceride concentrations (-4.9%). The monotherapy phase III studies have confirmed the efficacy with a decrease in LDL-C of 17.4% and have demonstrated an excellent safety and tolerability profile. The potential for a pharmacokinetic and/or pharmacodynamic interaction between ezetimibe and various statins and the efficacy and safety or the co-administration of ezetimibe and statins have been evaluated in different phase I/II studies: ezetimibe had no significant effect on the pharmacokinetics of simvastatin or atorvastatin. Ezetimibe 10 mg co-administrated with the starting dose of any statin induced a mean 18% additive LDL-C lowering effect. This additive 18% reduction in LDL-C is achieved in one step compared with the three steps necessary with statin monotherapy.     

Statin pleiotropy: fact or fiction?

Accumulating evidence from clinical trials and basic research indicates that statin therapy favorably influences a number of diverse clinical events through both effects related to lowering of LDL cholesterol levels and effects independent of the lowering of LDL cholesterol levels. The latter effects are referred to as pleiotropic. The full potential of this exciting class of drugs in vascular and nonvascular protection is only just being realized. The pleiotropic effects of the statins improve vascular relaxation, promote new vessel formation, and stabilize unstable plaques. Statins reduce glomerular injury, renal disease progression, insulin resistance, and bone resorption. Ezetimibe, a recently approved medication, enhances the lipid-lowering effects of the statins by lowering LDL and increasing HDL levels through its property of inhibiting absorption of cholesterol in the small intestine. These salutary effects of ezetimibe on statin levels presumably enhance the beneficial effects attributed to statin pleiotropy. It is noteworthy that the pleiotropic properties of the statins have been beneficial in a variety of diseases that involve a number of organs and organ systems. No other therapeutic agent can claim equally stellar results in such a wide variety of diseases. The common denominator in all of the diseases that have been shown to improve with statin pleiotropy could be arteriolar pathology due to hyperlipidemia, which improves in response to statins by a return of arteriolar function to normal rather than through statin pleiotropy. Recent reports indicate that higher doses of statins reverse atheromatous changes in the coronary artery when the LDL cholesterol level is lowered to well below 2.59 mmol/L (100 mg/dL). These results lend additional support to the probability that similar pathological changes that may be present in the small arteries and arterioles also can respond to adequate statin therapy. Statin pleiotropy: fact or fiction?     

The use of statins in optimising reduction of cardiovascular risk: focus on fluvastatin

Patients with widely differing degrees of cardiovascular risk can derive benefit from effective lipid-lowering therapy with statins, including patients with normal or low cholesterol levels. Clinical trials with fluvastatin have shown that it is effective in patients across a broad spectrum of cardiovascular risk. The lipid-lowering effects of fluvastatin are smaller than some statins, but major clinical outcome studies have consistently demonstrated morbidity and mortality benefits with reductions of low-density lipoprotein cholesterol of <30%. As treatment with statins is generally life-long and patients often receive multiple concomitant medications, optimal statin therapy should be well tolerated and serious consideration should be given to the avoidance of drug interactions. Although serious side-effects of statins are very rare, it is important that fluvastatin is less susceptible to drug interactions than other statins, because serious side-effects of statin therapy are generally associated with concomitant medications affecting statin metabolism. In addition, an extended-release formulation of fluvastatin has been developed to provide liver selectivity with a sustained exposure to the drug, thus improving its efficacy, and safety and tolerability profiles.     

Anti-inflammatory effects of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors (statins) in peritoneal dialysis patients.

OBJECTIVE: Elevated C-reactive protein (CRP) level is an independent predictor of all-cause and cardiovascular mortality in peritoneal dialysis (PD) patients. Statins have been demonstrated to have anti-inflammatory properties by virtue of their CRP lowering effects in hemodialysis patients. However, whether statins have an anti-inflammatory effect in PD patients is unknown. DESIGN: All prevalent PD patients at our center were reviewed. Eligible (257) patients were categorized into 2 groups: those on statin therapy (n = 137) and those not on statins (n = 120). Data were abstracted for hemoglobin, albumin, phosphates, cholesterol, CRP, Kt/V, and erythropoietin dose, along with relevant clinical data. RESULTS: The two groups had similar concentrations of hemoglobin, albumin, and phosphates. They were also matched for dialysis adequacy and duration of dialysis but the statin group patients were older (57 +/- 13 vs 52 +/- 17 years, p = 0.01). Serum cholesterol was lower in the statin group (4.74 +/- 1.05 vs 5.02 +/- 1.17 mmol/L, p < 0.05). Single-point (14 +/- 13 vs 19 +/- 18 mg/L, p < 0.02) and serially measured CRP (9 +/- 7.4 vs 12 +/- 10 mg/L, p < 0.02) levels were significantly lower in the statin group despite increased comorbidity (0.84 vs 0.54, p < 0.02) and greater incidence of diabetes mellitus (52% vs 25%, p < 0.01). CONCLUSION: Statin therapy is associated with low single-point and serially measured CRP levels in PD patients, thereby suggesting that their anti-inflammatory properties persist in PD. These data have implications for considering statin therapy in PD patients as an anti-inflammatory agent in addition to a cholesterol lowering drug.     

Randomized comparison of the efficacy and safety of cerivastatin and pravastatin in 1,030 hypercholesterolemic patients. The Cerivastatin Study Group

OBJECTIVE: To determine the relative efficacy and safety of cerivastatin and pravastatin in patients with type II hypercholesterolemia. PATIENTS AND METHODS: In this prospective, double-blind, parallel-group study, hypercholesterolemic patients were randomized to treatment with cerivastatin, 0.3 mg (n=250) or 0.4 mg (n=258), or pravastatin, 20 mg (n=266) or 40 mg (n=256), for 8 weeks. RESULTS: Cerivastatin, 0.3 mg, was significantly more effective than pravastatin, 20 mg, in reducing low-density lipoprotein (LDL) cholesterol from baseline (-29.6% vs -26.8%; P=.008). Cerivastatin, 0.4 mg, was significantly more effective than pravastatin, 40 mg, in reducing LDL cholesterol (-34.2% vs -30.3%; P<.001). A larger proportion of cerivastatin-treated patients had greater than 40% reductions in LDL cholesterol than those receiving pravastatin (11.1% vs 6.0%). The percentage of patients who achieved the National Cholesterol Education Program (NCEP) target was 71.3% with cerivastatin, 0.3 mg, compared with 67.5% with pravastatin, 20 mg, and 74.0% with cerivastatin, 0.4 mg, compared with 71.1% with pravastatin, 40 mg (no significant difference). Cerivastatin, 0.3 mg, reduced total cholesterol to a greater extent than did pravastatin, 20 mg (P<.03). Both agents reduced triglycerides and increased high-density lipoprotein cholesterol to a similar degree (no significant differences). Cerivastatin and pravastatin were well tolerated. CONCLUSIONS: Cerivastatin, 0.3 mg and 0.4 mg, showed greater efficacy than pravastatin, 20 mg and 40 mg, respectively, in lowering LDL cholesterol. Cerivastatin is safe and effective for patients with hypercholesterolemia who require aggressive LDL cholesterol lowering to achieve NCEP-recommended targets.     

Cerivastatin versus branded pravastatin in the treatment of primary hypercholesterolemia in primary care practice in Canada: a one-year, open-label, randomized, comparative study of efficacy, safety, and cost-effectiveness

BACKGROUND: Potential cost differences between statins are driven primarily by drug costs, differential lowering effects on low-density lipoprotein cholesterol (LDL-C) levels, and adverse drug interactions and reactions. OBJECTIVE: The purpose of this study was to compare the efficacy, safety, and direct treatment costs of cerivastatin and branded pravastatin in adult patients with primary hypercholesterolemia over a 1-year period. METHODS: This was a multicenter (48 sites), randomized, open-label, parallel-group, optional dose-titration study conducted in Canada. Patients aged 18 to 75 years with documented primary hypercholesterolemia (mean LDL-C > or = 160 mg/dL [> or = 4.5 mmol/L] and at least 1 fasting triglyceride measurement < or = 400 mg/dL [< or = 4.5 mmol/L]) that did not respond adequately to dietary intervention were enrolled. Patients who were on a diet at study entry were instructed to continue that diet for the duration of the study. Patients not following a diet were also entered into the study provided they had received previous dietary counseling and were unwilling or unable to comply with this dietary advice. Before randomization, treating physicians were required to record a target lipid level for each patient and then instructed to randomize patients to treatment with any dose and any titration schedule of cerivastatin or branded pravastatin according to their normal practice. Physicians were not required to titrate the study drug dose if the patient did not achieve the predefined target goal. Lipid analyses were conducted at baseline/randomization and at months 3, 6, 9, and 12. All samples drawn for lipid analyses were collected after a fast of > or = 10 hours. A cost-minimization approach was used to compare the direct treatment costs between cerivastatin and branded pravastatin. Since the analysis was from the perspective of the third-party payer (Ministries of Health), only costs attributed to the third-party payer were included. RESULTS: A total of 417 patients were randomized to once-daily treatment with cerivastatin 0.1 mg to 0.4 mg (n = 209) or branded pravastatin 10 mg to 40 mg (n = 208); 39 (9.4%) of patients discontinued prematurely, 19 (4.6%) because of an adverse event. The incidence of adverse events was similar for cerivastatin (73.6%) and branded pravastatin (74.9%). The majority of adverse events were mild or moderate and included headache, nausea, pain, and dizziness. Both cerivastatin and pravastatin were effective in lowering LDL-C to target levels (mean reduction 29.8% and 27.5%, respectively, P = 0.35). An LDL-C decrease of > or = 20% from baseline to end point was achieved in 74.2% of cerivastatin patients and 74.0% of pravastatin patients. The annualized direct hyperlipidemia treatment cost was 19% higher in the branded pravastatin group compared with the cerivastatin group. A sensitivity analysis designed to examine the impact of generic pricing on the cost-minimization analysis indicated that the cost difference between cerivastatin and generic pravastatin was not significant. CONCLUSIONS: Both cerivastatin and branded pravastatin were well tolerated and effective in lowering LDL-C by > or = 20% versus baseline. A cost savings in favor of cerivastatin was a reflection of the lower drug acquisition cost of cerivastatin compared with branded pravastatin.     

Ezetimibe: a novel option for lowering cholesterol

Elevated low-density lipoprotein (LDL)-cholesterol is associated with a significantly increased risk of coronary heart disease but lowering LDL-cholesterol to levels established in current National Cholesterol Education Program (NCEP) guidelines provides significant risk reduction. Nevertheless, many patients receiving lipid-lowering therapy, particularly those at highest coronary heart disease risk, do not reach LDL-cholesterol goals with their current medications. Ezetimibe (Zetia^®, Merck Schering-Plough) is the first of a new class of lipid-lowering drugs known as cholesterol absorption inhibitors. Ezetimibe has a favorable pharmacokinetic profile, which allows it to be administered once daily and to be given in conjunction with statins. In a series of randomized, controlled, multicenter studies, ezetimibe produced significant improvements in levels of LDL-cholesterol and other lipid parameters when used as monotherapy, with a safety profile comparable with that of placebo. Furthermore, coadministration of ezetimibe with a statin (simvastatin, atorvastatin, lovastatin, or pravastatin) was more effective than statin monotherapy in lowering LDL-cholesterol and improving other lipid parameters. Moreover, coadministration of ezetimibe with a statin allowed a greater percentage of patients to achieve treatment goals established in NCEP guidelines. The safety and side-effect profile of ezetimibe plus statin coadministration therapy was generally comparable with that of statin monotherapy. These studies establish ezetimibe as an effective lipid-lowering agent, which will likely be useful in the management of a broad range of patients with hypercholesterolemia. Ezetimibe can be used in conjunction with a statin at the beginning of therapy, or it can be added if patients do not achieve their LDL-cholesterol goal with statins alone.     

Ezetimibe: a novel option for lowering cholesterol

Elevated low-density lipoprotein (LDL)-cholesterol is associated with a significantly increased risk of coronary heart disease but lowering LDL-cholesterol to levels established in current National Cholesterol Education Program (NCEP) guidelines provides significant risk reduction. Nevertheless, many patients receiving lipid-lowering therapy, particularly those at highest coronary heart disease risk, do not reach LDL-cholesterol goals with their current medications. Ezetimibe (Zetia, Merck Schering-Plough) is the first of a new class of lipid-lowering drugs known as cholesterol absorption inhibitors. Ezetimibe has a favorable pharmacokinetic profile, which allows it to be administered once daily and to be given in conjunction with statins. In a series of randomized, controlled, multicenter studies, ezetimibe produced significant improvements in levels of LDL-cholesterol and other lipid parameters when used as monotherapy, with a safety profile comparable with that of placebo. Furthermore, coadministration of ezetimibe with a statin (simvastatin, atorvastatin, lovastatin, or pravastatin) was more effective than statin monotherapy in lowering LDL-cholesterol and improving other lipid parameters. Moreover, coadministration of ezetimibe with a statin allowed a greater percentage of patients to achieve treatment goals established in NCEP guidelines. The safety and side-effect profile of ezetimibe plus statin coadministration therapy was generally comparable with that of statin monotherapy. These studies establish ezetimibe as an effective lipid-lowering agent, which will likely be useful in the management of a broad range of patients with hypercholesterolemia. Ezetimibe can be used in conjunction with a statin at the beginning of therapy, or it can be added if patients do not achieve their LDL-cholesterol goal with statins alone.     

Statins,fibrates, nicotinic acid,cholesterol absorption inhibitors,anion‐exchange resins,omega‐3 fatty acids: which drugs for which patients?

Classes of lipid lowering drugs differ strongly with respect to the types of lipids or lipoproteins they predominantly affect. Statins inhibit the de-novo synthesis of cholesterol. Consequently, the liver produces less VLDL, and the serum concentration primarily of LDL cholesterol (but, to a lesser extent, also of triglycerides) is lowered. Further, statins somewhat increase HDL cholesterol. There is abundant evidence that statins lower the rate of cardiovascular events. Cardiovascular risk reduction is the better, the lower the LDL cholesterol values achieved with statin therapy are. Some evidence is available that anion exchange resins which also decrease LDL cholesterol decrease vascular risk, too. This is not the case for the ezetimibe, which strongly lowers LDL cholesterol: its potential to decrease vascular risk remains to be proven. In contrast evidence for cardiovascular risk reduction through the mainly triglyceride lowering fibrates as well as for niacin is available. Niacin is the most potent HDL increasing drug currently available and besides increasing HDL cholesterol efficaciously lowers triglycerides and LDL cholesterol. Large ongoing trials address the decisive question whether treatment with fibrates and niacin provides additional cardiovascular risk reduction when given in addition to statin treatment.     

A review of the efficacy of rosuvastatin in patients with type 2 diabetes

It has been estimated that 92% of individuals with type 2 diabetes, without cardiovascular disease (CVD), have a dyslipidaemic profile. Several guidelines on cardiovascular risk now recommend that patients with diabetes should be considered at high risk of CVD and should thus receive lipid-lowering therapy to reduce low-density lipoprotein cholesterol (LDL-C) to below 2.5 mmol/L. Since their introduction in 1987, statins have revolutionized the management of CVD. The most recent statin to be introduced, rosuvastatin, has been shown to be the most effective at lowering LDL-C, as well as consistently raising HDL-C across the 10-40 mg dose range. This has been confirmed by many studies, including the Measuring Effective Reductions in Cholesterol Using Rosuvastatin Therapy (MERCURY I) study in which rosuvastatin 10 mg was shown to be more effective than commonly used doses of other statins, both for LDL-C reduction and achieving treatment target goals. The effectiveness of rosuvastatin has also been studied in type 2 diabetes patients in three studies: the URANUS (Use of Rosuvastatin vs. Atorvastatin iN type 2 diabetes mellitUS), ANDROMEDA (A raNdomized, Double-blind study to compare Rosuvastatin [10 & 20 mg] and atOrvastatin [10 & 20 Mg] in patiEnts with type II DiAbetes) and CORALL (COmpare Rosuvastatin [10-40 mg] with Atorvastatin [20-80 mg] on apo B/apo A-1 ratio in patients with type 2 diabetes meLLitus and dyslipidaemia) studies. URANUS and ANDROMEDA showed rosuvastatin to be more effective than atorvastatin at reducing LDL-C and achieving treatment target goals. CORALL demonstrated rosuvastatin 10, 20 and 40 mg to be more effective at lowering LDL-C than 20, 40 and 80 mg of atorvastatin, respectively. Ongoing studies will evaluate whether these properties of rosuvastatin translate into beneficial effects on atherosclerosis and significant reductions in cardiovascular events.     

The potential role of HMG-CoA reductase inhibitors in pediatric nephrotic syndrome

OBJECTIVE: To evaluate the safety and efficacy of the hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) as a potential treatment option for the dyslipidemia associated with childhood nephrotic syndrome. DATA SOURCES: Searches of MEDLINE (1966-April 2004), Cochrane Library, International Pharmaceutical Abstracts (1977-April 2004), and an extensive manual review of journals were performed using the key search terms nephrotic syndrome, familial hypercholesterolemia, dyslipidemia, and HMG-CoA reductase inhibitor. STUDY SELECTION AND DATA EXTRACTION: Two prospective uncontrolled studies evaluating the safety and efficacy of statin therapy in pediatric nephrotic syndrome were included. DATA SYNTHESIS: While an extensive amount of data is available in adult nephrotic syndrome in which statin therapy decreases total plasma cholesterol 22-39%, low-density lipoprotein cholesterol (LDL-C) 27-47%, and total plasma triglycerides 13-38%, only 2 small uncontrolled studies have been conducted evaluating the utility of these agents in pediatric nephrotic syndrome. These studies indicate that statins are capable of safely reducing total cholesterol up to 42%, LDL-C up to 46%, and triglyceride levels up to 44%. CONCLUSIONS: Lowering cholesterol levels during childhood may reduce the risk for atherosclerotic changes and may thus be of benefit in certain patients with nephrotic syndrome. Statins have demonstrated short-term safety and efficacy in the pediatric nephrotic syndrome population. Implementing pharmacologic therapy with statins in children with nephrotic syndrome must be done with care until controlled studies are conducted in this population.     

Treatment of the elderly with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors: focus on drug interactions

With the aging of the population, death from coronary heart disease (CHD) and stroke has become more prevalent. Cardiovascular disease (CVD) risk factors, such as hypertension, obesity, and diabetes mellitus increase with age as well. Recent secondary-prevention studies have established the positive effect of statins in decreasing the risk of CHD mortality through the lowering of cholesterol. Statins have an excellent safety record, at least with users under age 65, and provide a cheaper alternative to more costly medical options. The most serious side effect associated with their use is myopathy, which is infrequent. Drug interactions have been found with drugs that compete for the same CYP450 isoenzymes as statins. Several drugs have been shown to significantly inhibit the CYP3A4 pathway; in combination with statins such as lovastatin, simvastatin, atorvastatin, and cerivastatin, they have been shown to elevate serum concentrations of these statins, or may increase the risk of myopathy. Alternatively, other drugs can inhibit the CYP2C9 pathway and may elevate serum concentration of fluvastatin. Due to the number of medications the elderly receive, an understanding of the various metabolic pathways is of vital importance to minimize the potential for drug interactions. The elderly population, while at high risk for CVD, is currently undertreated. Statins can effectively lower low-density lipoprotein cholesterol levels and lessen the risk of CVD for this population.