Absence of effect of simvastatin on the progression of lens opacities in a randomised placebo controlled study. Oxford Cholesterol Study Group

Associations of different types of statins with the risk of open-angle glaucoma: a systematic review and network meta-analysis

PURPOSE

Previous studies implied that different types of statins may pose divergent impacts on the risk of glaucoma onset. This study aimed to comprehensively evaluate the effects of various statins on the risk of glaucoma occurrence.

METHODS

PubMed, Cochrane CENTRAL, Embase, and Web of Science were searched from February 1994 to February 2024. We included studies that investigated the effects of various types of statins, fibrates, ezetimibe, cholestyramine, niacin, PCSK9 inhibitors, omega-3 fatty acids, and any cholesterol-lowering medications on glaucoma onset or progression. The revised Cochrane risk-of-bias tool for randomized trials (RoB 2.0) and the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-1) tool were used to assess the quality of randomized controlled trials (RCTs) and non-RCTs, respectively. The frequentist network meta-analysis framework was utilized to evaluate the comparative effectiveness, with the random effects model applied.

RESULTS

This network meta-analysis comprised 12 studies, encompassing 262,217 individuals and including cholesterol-lowering medications such as statins, fibrates, ezetimibe, cholestyramine, niacin, and omega-3 fatty acids. Our findings demonstrate that comparing to the placebo, rosuvastatin (risk ratio [RR], 1.23; 95% confidence interval [CI], 1.03 to 1.46), simvastatin (RR, 1.21; 95% CI, 1.02 to 1.43), and pravastatin (RR, 1.20; 95% CI, 1.01 to 1.43) increased the risk of glaucoma onset with statistical significance.

CONCLUSION

Rosuvastatin, simvastatin, and pravastatin were each associated with a significantly increased risk of glaucoma onset. We advise medical practitioners to exercise caution when prescribing these specific statins for patients who are at risk of developing glaucoma.

KEY MESSAGES

What is known Previous studies have suggested a link between statins and the risk of developing glaucoma. However, there is still ongoing debate regarding the specific effects of each type of statin on the onset of glaucoma. What is new This network meta-analysis comprehensively evaluated the effects of various statins on the risk of glaucoma onset. Rosuvastatin, simvastatin, and pravastatin were associated with a significantly increased risk of glaucoma onset.

Association between long-term statin use and cataract surgery: a nationwide study on 505 105 cataract surgery patients

AIMS

To assess the association between statin use and cataract surgery according to different statin treatment durations in patients with different cardiovascular risk profiles.

METHODS AND RESULTS

We performed a nested case-control study using Danish registries, covering the period from 1 January 1996 to 31 December 2020. We defined cases as surgically treated cataract patients, matched in a 1:1 ratio by sex and age with controls not undergoing cataract surgery. The exposure of interest was statin use in different durations (1, 5 and 10 years) compared with never use of statins. Conditional logistic regression provided adjusted HRs and corresponding 95% CIs in subgroups defined by established atherosclerotic cardiovascular disease, diabetes, hypertension and individuals without these comorbidities. We identified 505 150 cataract surgery cases and found no increased HR of cataract surgery with statin treatment at any duration in any of the subgroups with established atherosclerotic cardiovascular disease, diabetes or hypertension.

CONCLUSION

Our findings do not support a possible association between long-term statin use and cataract in patients with established atherosclerotic cardiovascular disease, diabetes or hypertension. Although we found an association between statin use and cataract in individuals without these comorbidities, increasing durations of statin use did not yield higher cataract surgery rates.

The Effect of Statins on Ocular Disorders: A Systematic Review of Randomized Controlled Trials

AIM

Statins have been established in the market not only due to their ability to lower plasma cholesterol levels but also due to their pleiotropic effects. In the literature, there is a controversy regarding the role of statins in ophthalmology. We aimed to systematically address the possible effect of statin therapy on ocular diseases and to identify if there is a beneficial relationship.

METHODS

We searched PubMed and Cochrane Library databases up to 31 December 2022 for studies evaluating the effect of statins on ocular diseases. We included all relevant Randomized Control Trials (RCTs) that have been conducted in the adult population. PROSPERO registration number: CRD42022364328.

RESULTS

Nineteen RCTs were finally considered eligible for this systematic review, with a total of 28,940 participants. Ten studies investigated the role of simvastatin, suggesting a lack of cataractogenic effect and a possible protective role in cataract formation, retinal vascular diseases, and especially diabetic retinopathy, age-related macular disease progression, and non-infectious uveitis. Four studies investigated lovastatin, showing no cataractogenic effect. Three studies examined atorvastatin, revealing conflicting results regarding diabetic retinopathy. Two studies examined rosuvastatin, indicating a possibly harmful effect on lenses and a significant protective effect on retinal microvasculature.

CONCLUSIONS

Based on our findings, we believe that statins have no cataractogenic effect. There are indications that statins may have a protective role against cataract formation, AMD, diabetic retinopathy progression, and non-infectious uveitis. However, our results were insufficient for any robust conclusion. Future RCTs, with large sample sizes, on the current topic are therefore recommended to provide more solid evidence.

Association of Common and Rare Genetic Variation in the 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene and Cataract Risk

Background Results from animal models and observational studies have raised concerns regarding the potential cataractogenic effects of statin treatment. We investigated whether common and rare genetic variants in HMGCR are associated with cataract risk, to gauge the likely long-term effects of statin treatment on lenticular opacities. Methods and Results We used genotyping data and exome sequencing data of unrelated European individuals in the UK Biobank to test the association between genetically proxied inhibition of HMGCR and cataract risk. First, we constructed an HMGCR genetic score consisting of 5 common variants weighted by their association with low-density lipoprotein cholesterol. Second, we analyzed exome sequencing data to identify carriers of predicted loss-of-function mutations in HMGCR. Common and rare variants in aggregate were then tested for association with cataract and cataract surgery. In an analysis of >402 000 individuals, a 38.7 mg/dL (1 mmol/L) reduction in low-density lipoprotein C by the HMGCR genetic score was associated with higher risk for cataract (odds ratio, 1.14 [95% CI, 1.00-1.39], P=0.045) and cataract surgery (odds ratio, 1.25 [95% CI, 1.06-1.48], P=0.009). Among 169 172 individuals with HMGCR sequencing data, we identified 32 participants (0.02%), who carried a rare HMGCR predicted loss-of-function variant. Compared with noncarriers, heterozygous carriers of HMGCR predicted loss-of-function had a higher risk of developing cataract (odds ratio, 4.54 [95% CI, 1.96-10.53], P=0.001) and cataract surgery (odds ratio, 5.27 [95% CI, 2.27-12.25], P=5.37×10-4). In exploratory analyses, we found no significant association between genetically proxied inhibition of PCSK9, NPC1L1, or circulating low-density lipoprotein cholesterol levels (P>0.05 for all) and cataract risk. Conclusions We found that genetically proxied inhibition of the HMGCR gene mimicking long-term statin treatment associated with higher risk of cataract. Clinical trials with longer follow-up are needed to confirm these findings.

Simvastatin alleviates epithelial‑mesenchymal transition and oxidative stress of high glucose‑induced lens epithelial cells in vitro by inhibiting RhoA/ROCK signaling

Diabetic cataracts (DC) is one of the main causes of blindness among patients with diabetes mellitus. The aim of the present study was to examine the effect of simvastatin on lens epithelial cells in DC and the underlying mechanism. The viability of SRA01/04 cells treated with different concentrations of simvastatin was detected using a Cell Counting Kit-8 assay before and after high glucose (HG) treatment. The expression levels of E-cadherin, N-cadherin, Vimentin and α-smooth muscle actin (α-SMA), proteins associated with epithelial-mesenchymal transition (EMT), in addition to RhoA, Rho-associated kinases (ROCK)1 and ROCK2, proteins related to RhoA/ROCK signaling, were also measured in SRA01/04 cells treated with HG and simvastatin, with or without U46619, using western blot analysis. DCFH-DA dyes, superoxide dismutase (SOD) and glutathione (GSH)/glutathione disulfide (GSSG) kits were used to measure the levels of oxidative stress parameters in SRA01/04 cells treated with HG and simvastatin with or without U46619. The cell viability of SRA01/04 cells treated with simvastatin was found to be significantly elevated after HG treatment. The protein expression levels of E-cadherin were increased but those of N-cadherin, Vimentin and α-SMA decreased after HG and simvastatin treatment, and this was reversed by U46619. The levels of SOD and GSH-GSSG were found to be increased whereas reactive oxygen species levels were decreased, effects that were reversed by U46619. Additionally, the protein expression levels of RhoA, ROCK1 and ROCK2 were markedly decreased. These findings provided evidence that simvastatin increased HG-induced SRA01/04 cell viability and exerted inhibitory effects on EMT and oxidative stress that occurs during DC.

Statins for children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is one of the most common inherited metabolic diseases and is an autosomal dominant disorder meaning heterozygotes, or carriers, are affected. Those who are homozygous have severe disease. The average worldwide prevalence of heterozygous familial hypercholesterolemia is at least 1 in 500, although recent genetic epidemiological data from Denmark and next generation sequencing data suggest the frequency may be closer to 1 in 250. Diagnosis of familial hypercholesterolemia in children is based on elevated total cholesterol and low-density lipoprotein cholesterol levels or DNA-based analysis, or both. Coronary atherosclerosis has been detected in men with heterozygous familial hypercholesterolemia as young as 17 years old and in women with heterozygous familial hypercholesterolemia at 25 years old. Since the clinical complications of atherosclerosis occur prematurely, especially in men, lifelong treatment, started in childhood, is needed to reduce the risk of cardiovascular disease. In children with the disease, diet was the cornerstone of treatment but the addition of lipid-lowering medications has resulted in a significant improvement in treatment. Anion exchange resins, such as cholestyramine and colestipol, were found to be effective, but they are poorly tolerated. Since the 1990s studies carried out on children aged 6 to 17 years with heterozygous familial hypercholesterolemia have demonstrated significant reductions in their serum total and low-density lipoprotein cholesterol levels. While statins seem to be safe and well-tolerated in children, their long-term safety in this age group is not firmly established. This is an update of a previously published version of this Cochane Review.

OBJECTIVES

To assess the effectiveness and safety of statins in children with heterozygous familial hypercholesterolemia.

SEARCH METHODS

Relevant studies were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline. Date of most recent search: 04 November 2019.

SELECTION CRITERIA

Randomized and controlled clinical studies including participants up to 18 years old, comparing a statin to placebo or to diet alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

We found 26 potentially eligible studies, of which we included nine randomized placebo-controlled studies (1177 participants). In general, the intervention and follow-up time was short (median 24 weeks; range from six weeks to two years). Statins reduced the mean low-density lipoprotein cholesterol concentration at all time points (high-quality evidence). There may be little or no difference in liver function (serum aspartate and alanine aminotransferase, as well as creatinine kinase concentrations) between treated and placebo groups at any time point (low-quality evidence). There may be little or no difference in myopathy (as measured in change in creatinine levels) (low-quality evidence) or clinical adverse events (moderate-quality evidence) with statins compared to placebo. One study on simvastatin showed that this may slightly improve flow-mediated dilatation of the brachial artery (low-quality evidence), and on pravastatin for two years may have induced a regression in carotid intima media thickness (low-quality evidence). No studies reported rhabdomyolysis (degeneration of skeletal muscle tissue) or death due to rhabdomyolysis, quality of life or compliance to study medication.

AUTHORS' CONCLUSIONS

Statin treatment is an effective lipid-lowering therapy in children with familial hypercholesterolemia. Few or no safety issues were identified. Statin treatment seems to be safe in the short term, but long-term safety remains unknown. Children treated with statins should be carefully monitored and followed up by their pediatricians and their care transferred to an adult lipidologist once they reach 18 years of age. Large long-term randomized controlled trials are needed to establish the long-term safety issues of statins.

Statins in ophthalmology

Statins, 3-hydroxy-3-methyl-gutaryl coenzyme A reductase inhibitors, are a class of lipid-lowering drugs with anti-inflammatory, immunomodulatory, and vascular effects. Statins are increasingly being used in the treatment of a variety of medical conditions. We examine the actions of statins on the eye and its associated ophthalmic disorders. Statins can be synthetic or nonsynthetic, and their differentiating derivations may contribute to their varying cholesterol-lowering and pleiotropic effects. There is conflicting evidence on the ocular therapeutic and adverse effects of the statins. Statins may play a role in reducing the burden of dry eye, corneal ulcer scarring, thyroid-associated orbitopathy, glaucoma, uveitis and other associated ocular inflammatory states, cataract, proliferative vitreoretinopathy, diabetic retinopathy, macular degeneration, and choroidal melanoma. Topical preparations of statins can be formulated, thereby extending the range of ocular diseases that may be amenable to treatment. Statins have a relatively safe side effect profile, but rare and serious adverse reactions have been reported with their usage in ophthalmology, including myopathies and rhabdomyolysis with acute renal failure.

Plasma proprotein convertase subtilisin/kexin type 9 inhibitors and cataract risk: A systematic review and meta-analysis

BACKGROUND

The marked decrease in LDL-C levels produced by the inhibitors of the plasma proprotein convertase subtilisin/kexin type 9 (iPCSK9) could be associated with an increased risk of cataracts.

METHODS

A meta-analysis was performed that included randomised clinical trials controlled with iPCSK9, alone, or in combination with other lipid-lowering drugs, which reported new cases of cataracts, by searching PubMed/Medline, databases of EMBASE and Cochrane Clinical Trials. A fixed-effect model was used, and a meta-regression was carried out evaluating the relationship between intra-treatment LDL-C and the risk of developing cataracts.

RESULTS

Five eligible studies of iPCSK9 including 83,492 patients were taken into account for the analysis, and 531 new cases of cataracts in iPCSK9 group vs. 532 in placebo group were diagnosed. The iPCSK9 therapy was not associated with an increased risk of cataracts [OR: 0.96, 95% CI: 0.85-1.08; P=.86, I²: 0%]. Likewise, no significant association was found between on-treatment LDL-C levels, differences between study arms, and new cases of cataracts.

CONCLUSION

In this analysis, the use of iPCSK9 was not associated with an increased risk of cataracts.

The protective effect of simvastatin against ultraviolet B-induced corneal endothelial cell death

Purpose:

Excessive ultraviolet B (UVB) exposure causing corneal endothelium injury, including apoptosis, is a serious condition. Therefore, drugs that can inhibit apoptosis in corneal endothelial cells represent an effective strategy. Simvastatin is widely used as a specific inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA reductase, can reduce levels of low density lipoprotein (LDL) cholesterol, and exerts anti-inflammatory effects. However, the protective effect of simvastatin on corneal endothelial cells remains unclear. Therefore, the aim of this study was to elucidate whether UVB promotes the initiation of apoptosis in corneal endothelial cells and injury reversible by simvastatin treatment.

Methods:

We detected the cell viability, subG1 population, and caspase-3 activity.

Results:

Results showed that simvastatin alleviates UVB-induced cell death, cell apoptosis, and caspase-3 activity.

Conclusion:

Our findings indicated that simvastatin alleviated UVB-induced corneal endothelial cell apoptosis via caspase-3 activity.

Adverse effects of statin therapy: perception vs. the evidence - focus on glucose homeostasis, cognitive, renal and hepatic function, haemorrhagic stroke and cataract

Aims

To objectively appraise evidence for possible adverse effects of long-term statin therapy on glucose homeostasis, cognitive, renal and hepatic function, and risk for haemorrhagic stroke or cataract.

Methods and results

A literature search covering 2000-2017 was performed. The Panel critically appraised the data and agreed by consensus on the categorization of reported adverse effects. Randomized controlled trials (RCTs) and genetic studies show that statin therapy is associated with a modest increase in the risk of new-onset diabetes mellitus (about one per thousand patient-years), generally defined by laboratory findings (glycated haemoglobin ≥6.5); this risk is significantly higher in the metabolic syndrome or prediabetes. Statin treatment does not adversely affect cognitive function, even at very low levels of low-density lipoprotein cholesterol and is not associated with clinically significant deterioration of renal function, or development of cataract. Transient increases in liver enzymes occur in 0.5-2% of patients taking statins but are not clinically relevant; idiosyncratic liver injury due to statins is very rare and causality difficult to prove. The evidence base does not support an increased risk of haemorrhagic stroke in individuals without cerebrovascular disease; a small increase in risk was suggested by the Stroke Prevention by Aggressive Reduction of Cholesterol Levels study in subjects with prior stroke but has not been confirmed in the substantive evidence base of RCTs, cohort studies and case-control studies.

Conclusion

Long-term statin treatment is remarkably safe with a low risk of clinically relevant adverse effects as defined above; statin-associated muscle symptoms were discussed in a previous Consensus Statement. Importantly, the established cardiovascular benefits of statin therapy far outweigh the risk of adverse effects.

Use of Lipid-Lowering Drugs and the Risk of Cataract: A Population-Based Nested Case-Control Study

Eye lens membrane cells require high cholesterol concentrations that might be counteracted by lipid-lowering drugs. Using a nationwide database, we conducted a nested case-control study to evaluate the risk of cataract development associated with the use of lipid-lowering drugs. Patients aged 45 years and over with first cataract surgery in 2014 (cases) and up to four controls matched on age, gender, diabetes, hypothyroidism, glucocorticoid use, cardiovascular risk, and area of residence were included in the study. Among the 2,811 cases and 11,106 matched controls included, analyses showed a significantly increased risk of cataract surgery for a cumulative exposure to fibrates exceeding 5 years (adjusted odds ratio (aOR) 1.58; 95% confidence interval (CI): 1.17-2.15), unlike cumulative exposure to statins, whatever the dose or duration of treatment (aORs from 1.00-1.08, none being significant). This study highlighted an increased risk of cataract surgery with prolonged use of fibrates but not of statins.

Statins for children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is one of the most common inherited metabolic diseases and is an autosomal dominant disorder meaning heterozygotes, or carriers, are affected. Those who are homozygous have severe disease. The average worldwide prevalence of heterozygous familial hypercholesterolemia is at least 1 in 500, although recent genetic epidemiological data from Denmark and next generation sequencing data suggest the frequency may be closer to 1 in 250. Diagnosis of familial hypercholesterolemia in children is based on elevated total cholesterol and low-density lipoprotein cholesterol levels or DNA-based analysis, or both. Coronary atherosclerosis has been detected in men with heterozygous familial hypercholesterolemia as young as 17 years old and in women with heterozygous familial hypercholesterolemia at 25 years old. Since the clinical complications of atherosclerosis occur prematurely, especially in men, lifelong treatment, started in childhood, is needed to reduce the risk of cardiovascular disease. In children with the disease, diet was the cornerstone of treatment but the addition of lipid-lowering medications has resulted in a significant improvement in treatment. Anion exchange resins, such as cholestyramine and colestipol, were found to be effective, but they are poorly tolerated. Since the 1990s studies carried out on children aged 6 to 17 years with heterozygous familial hypercholesterolemia have demonstrated significant reductions in their serum total and low-density lipoprotein cholesterol levels. While statins seem to be safe and well-tolerated in children, their long-term safety in this age group is not firmly established. This is an update of a previously published version of this Cochane Review.

OBJECTIVES

To assess the effectiveness and safety of statins in children with heterozygous familial hypercholesterolemia.

SEARCH METHODS

Relevant studies were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline.Date of most recent search: 20 February 2017.

SELECTION CRITERIA

Randomized and controlled clinical studies including participants up to 18 years old, comparing a statin to placebo or to diet alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

We found 26 potentially eligible studies, of which we included nine randomized placebo-controlled studies (1177 participants). In general, the intervention and follow-up time was short (median 24 weeks; range from six weeks to two years). Statins reduced the mean low-density lipoprotein cholesterol concentration at all time points (moderate quality evidence). Serum aspartate and alanine aminotransferase, as well as creatinine kinase concentrations, did not differ between treated and placebo groups at any time point (low quality evidence). The risks of myopathy (low quality evidence) and clinical adverse events (moderate quality evidence) were very low and also similar in both groups. In one study simvastatin was shown to improve flow-mediated dilatation of the brachial artery (low quality evidence), and in another study treatment with pravastatin for two years induced a significant regression in carotid intima media thickness (low quality evidence).

AUTHORS' CONCLUSIONS

Statin treatment is an effective lipid-lowering therapy in children with familial hypercholesterolemia. No significant safety issues were identified. Statin treatment seems to be safe in the short term, but long-term safety remains unknown. Children treated with statins should be carefully monitored and followed up by their pediatricians and their care transferred to an adult lipidologist once they reach 18 years of age. Large long-term randomized controlled trials are needed to establish the long-term safety issues of statins.

Statin Use and the Risk of Cataracts: A Systematic Review and Meta-Analysis

BACKGROUND

Cataracts are the main cause of poor vision and blindness worldwide. The effects of statin administration on cataracts remain debated. Therefore, we conducted a systematic review and meta-analysis to determine whether statin use affects the risk of cataracts.

METHODS AND RESULTS

We performed a systematic search of the electronic databases PubMed, EMBASE, and the Cochrane Library through January 2016. Weighted averages were reported as relative risk values with 95% CIs. Statistical heterogeneity scores were assessed with the standard Cochran's Q test and the I² statistic. A total of 6 cohort studies, 6 case-control studies, and 5 randomized controlled trials, together involving more than 313 200 patients, were included in our study. The pooled estimates of cohort studies indicated that the use of statins moderately increases the risk of cataracts (relative risk, 1.13; 95% CI, 1.01-1.25). The pooled estimates of case-control studies (relative risk=1.10, 95% CI, 0.99-1.23) and randomized controlled trials (relative risk, 0.89; 95% CI, 0.72-1.10) indicated that the use of statins does not increase the risk of cataracts. The sensitivity analysis confirmed the stability of the results. Heterogeneity was found among the cohort and case-control studies.

CONCLUSIONS

Based on the present meta-analysis of these studies, we could only conclude that there is no clear evidence showing that statin use increases the risk of cataracts. The most likely case is that there is no association between statin use and cataracts. Because of the considerable benefits of statins in cardiovascular patients, this issue should not deter their use.

Interpretation of the evidence for the efficacy and safety of statin therapy

This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence that is available from randomised controlled trials yields reliable information about both the efficacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse effects reflect a failure to recognise the limitations of other sources of evidence about the effects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the first) that it continues to be taken. The absolute benefits of statin therapy depend on an individual's absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an effective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefit) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefit) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefits would accrue with more prolonged therapy, and these benefits persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy-ie, adverse effects of the statin-are myopathy (defined as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an effective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50-100 new cases of diabetes, and 5-10 haemorrhagic strokes. However, any adverse impact of these side-effects on major vascular events has already been taken into account in the estimates of the absolute benefits. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50-100 patients (ie, 0·5-1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown definitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further findings that emerge about the effects of statin therapy would not be expected to alter materially the balance of benefits and harms. It is, therefore, of concern that exaggerated claims about side-effect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating.

Statin use and risk of cataract: A nested case-control study within a healthcare database

BACKGROUND AND AIMS

We aimed to assess the association between exposure to statins and hospitalization for cataract.

METHODS

A population-based, nested case-control study was performed on a cohort of 134,441 patients from Lombardy (Italy), newly treated with statins between 2005 and 2007. Cases were patients hospitalized for cataract or lens extraction surgery after initial statin prescription until December 31, 2012. For each case patient, up to 5 controls were randomly selected from the cohort and matched by gender, age at cohort entry, and date of index prescription. Logistic regression was used to model the outcome risk associated with low (proportion of days covered, PDC 25-49%), intermediate (PDC 50-74%), and high (PDC ≥ 75%) adherence compared with very-low adherence (PDC < 25%).

RESULTS

1334 case patients were matched to 6601 controls. Mean age (SD) of cases and controls was about 70 years (9 years) and 51% of them were men. There was a slight but continuous trend toward an increased risk of cataract as adherence to statin therapy increased in the adjusted risk models, with a significant odds ratio of 1.19 (95% CI 1.01-1.40%) for PDC 50-74% and 1.20 (95% CI 1.02-1.40) for PDC ≥ 75% vs. PDC < 25%, respectively. There was no statistical evidence that the effect of statins on cataract risk differed according to statin potency at starting therapy.

CONCLUSIONS

Statin therapy was associated with a modestly increased risk of cataract surgery. Nevertheless, in view of the overwhelming benefit of statins for reduction of CV events, clinical practice for statins therapy does not need to change.

The safety of ezetimibe and simvastatin combination for the treatment of hypercholesterolemia

INTRODUCTION

In the light of the most recent and stricter dyslipidemia treatment guidelines, the need for combination hypolipidemic therapy is increasing. Ezetimibe plus simvastatin is available as a fixed dose therapy offering an efficient hypolipidemic treatment choice. Based on the positive results of the IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) trial, the use of this drug combination is expected to increase in the next years.

AREAS COVERED

This review discusses the current evidence regarding the safety of ezetimibe/simvastatin combination. Current evidence regarding possible associated side effects (musculoskeletal, gastrointestinal, endocrine, hematological, renal, ophthalmologic, allergic, malignancy) and drug interactions of this combination is thoroughly discussed.

EXPERT OPINION

Ezetimibe and simvastatin treatment, either as a single pill or the combined use of the individual compounds, offers limited additional risk compared with simvastatin monotherapy and comprises a safe and efficient choice for dyslipidemia treatment in high-risk and diabetic patients.

Long-Term Safety and Efficacy of Lowering Low-Density Lipoprotein Cholesterol With Statin Therapy: 20-Year Follow-Up of West of Scotland Coronary Prevention Study

BACKGROUND

Extended follow-up of statin-based low-density lipoprotein cholesterol lowering trials improves the understanding of statin safety and efficacy. Examining cumulative cardiovascular events (total burden of disease) gives a better appreciation of the clinical value of statins. This article evaluates the long-term impact of therapy on mortality and cumulative morbidity in a high-risk cohort of men.

METHODS AND RESULTS

The West of Scotland Coronary Prevention Study was a primary prevention trial in 45- to 64-year-old men with high low-density lipoprotein cholesterol. A total of 6595 men were randomized to receive pravastatin 40 mg once daily or placebo for an average of 4.9 years. Subsequent linkage to electronic health records permitted analysis of major incident events over 20 years. Post trial statin use was recorded for 5 years after the trial but not for the last 10 years. Men allocated to pravastatin had reduced all-cause mortality (hazard ratio, 0.87; 95% confidence interval, 0.80-0.94; P=0.0007), attributable mainly to a 21% decrease in cardiovascular death (hazard ratio, 0.79; 95% confidence interval, 0.69-0.90; P=0.0004). There was no difference in noncardiovascular or cancer death rates between groups. Cumulative hospitalization event rates were lower in the statin-treated arm: by 18% for any coronary event (P=0.002), by 24% for myocardial infarction (P=0.01), and by 35% for heart failure (P=0.002). There were no significant differences between groups in hospitalization for noncardiovascular causes.

CONCLUSION

Statin treatment for 5 years was associated with a legacy benefit, with improved survival and a substantial reduction in cardiovascular disease outcomes over a 20-year period, supporting the wider adoption of primary prevention strategies.

Statin Use and Incident Cataract Surgery: A Case-Control Study

PURPOSE

To determine the association between statin use and incident cataract surgery.

METHODS

Using the resources of the Rochester Epidemiology Project, a retrospective population-based, case-control study was performed. Cases included 6024 county residents aged 50 years and older who had first-eye cataract surgery between 1 January 2004 and 31 December 2011. Controls included residents who had never had cataract surgery and were matched to cases by age, sex, and index date within 1 month of surgery. Statin medications continuously prescribed for at least 1 year before the surgery date (cases) or index date (controls) were examined. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models.

RESULTS

There were 2557 (42%) statin users among cases having cataract surgery compared to 2038 (34%) statin users among controls never having had cataract surgery (p < 0.0001). Incident cataract surgery was significantly associated with increased odds of statin use (OR 1.29, 95% CI 1.19-1.55) after adjusting for age, sex, diabetes, cardiovascular disease, cerebrovascular disease, peripheral vascular disease, renal disease, oral and inhaled steroid use, and selective serotonin reuptake inhibitor use. The association was consistent in both subgroups of women (OR 1.34, 95%CI 1.22-1.49) and men (OR 1.17, 95% CI 1.05-1.30).

CONCLUSIONS

Incident cataract surgery was associated with increased odds of statin use, and underscores the possibility that increasing statin use could be contributing to rising rates of cataract surgery.

Biochemistry of Statins

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Elevated blood lipids may be a major risk factor for CVD. Due to consistent and robust association of higher low-density lipoprotein (LDL)-cholesterol levels with CVD across experimental and epidemiologic studies, therapeutic strategies to decrease risk have focused on LDL-cholesterol reduction as the primary goal. Current medication options for lipid-lowering therapy include statins, bile acid sequestrants, a cholesterol-absorption inhibitor, fibrates, nicotinic acid, and omega-3 fatty acids, which all have various mechanisms of action and pharmacokinetic properties. The most widely prescribed lipid-lowering agents are the HMG-CoA reductase inhibitors, or statins. Since their introduction in the 1980s, statins have emerged as the one of the best-selling medication classes to date, with numerous trials demonstrating powerful efficacy in preventing cardiovascular outcomes (Kapur and Musunuru, 2008 [1]). The statins are commonly used in the treatment of hypercholesterolemia and mixed hyperlipidemia. This chapter focuses on the biochemistry of statins including their structures, pharmacokinetics, and mechanism of actions as well as the potential adverse reactions linked to their clinical uses.

Effect of Randomized Lipid Lowering With Simvastatin and Ezetimibe on Cataract Development (from the Simvastatin and Ezetimibe in Aortic Stenosis Study)

Recent American College of Cardiology/American Heart Association guidelines on statin initiation on the basis of total atherosclerotic cardiovascular disease risk argue that the preventive effect of statins on cardiovascular events outweigh the side effects, although this is controversial. Studies indicate a possible effect of statin therapy on reducing risk of lens opacities. However, the results are conflicting. The Simvastatin and Ezetimibe in Aortic Stenosis study (NCT00092677) enrolled 1,873 patients with asymptomatic aortic stenosis and no history of diabetes, coronary heart disease, or other serious co-morbidities were randomized (1:1) to double-blind 40 mg simvastatin plus 10 mg ezetimibe versus placebo. The primary end point in this substudy was incident cataract. Univariate and multivariate Cox models were used to analyze: (1) if the active treatment reduced the risk of the primary end point and (2) if time-varying low-density lipoproteins (LDL) cholesterol lowering (annually assessed) was associated with less incident cataract per se. During an average follow-up of 4.3 years, 65 patients (3.5%) developed cataract. Mean age at baseline was 68 years and 39% were women. In Cox multivariate analysis adjusted for age, gender, prednisolone treatment, smoking, baseline LDL cholesterol and high sensitivity C-reactive protein; simvastatin plus ezetimibe versus placebo was associated with 44% lower risk of cataract development (hazard ratio 0.56, 95% confidence interval 0.33 to 0.96, p = 0.034). In a parallel analysis substituting time-varying LDL-cholesterol with randomized treatment, lower intreatment LDL-cholesterol was in itself associated with lower risk of incident cataract (hazard ratio 0.78 per 1 mmol/ml lower total cholesterol, 95% confidence interval 0.64 to 0.93, p = 0.008). In conclusion, randomized treatment with simvastatin plus ezetimibe was associated with a 44% lower risk of incident cataract development. This effect should perhaps be considered in the risk-benefit ratio of statin treatment.

Statin use and risk for cataract: a nested case-control study of 2 populations in Canada and the United States

BACKGROUND

In current literature the association between statin use and cataracts is inconsistent and controversial. We sought to further examine the effect of statin use on the risk of cataract and need for surgical intervention in 2 North American populations.

METHODS

This retrospective nested case-control study derived data from the British Columbia (BC) Ministry of Health databases from 2000-2007 and the IMS LifeLink database from 2001-2011 to form 2 patient cohorts. The BC cohort was comprised of female and male patients; 162,501 patients were matched with 650,004 control subjects. The IMS LifeLink cohort was comprised of male patients aged 40-85 years; 45,065 patients were matched with 450,650 control subjects. Patients with statin use for > 1 year before the initial ophthalmology visit were identified. Diagnosis and surgical management of cataract were followed. Conditional logistic regression models were used to analyze data.

RESULTS

For the BC cohort, the crude rate ratio (RR) for use of any statin was 1.30, and the adjusted RR was 1.27 (95% confidence interval, 1.24-1.30). The adjusted RRs for each individual statin were all statistically significant. For the IMS LifeLink cohort, the crude RR for use of any statin was 1.13, and the adjusted RR was 1.07 (95% confidence interval, 1.04-1.10).

CONCLUSIONS

This study demonstrates that statin use is significantly associated with cataract requiring surgical intervention. This relationship was consistent in both North American cohorts. Further assessment of this relationship is recommended, especially because of increased statin use and the importance of acceptable vision in old age when cardiovascular disease is common.

Statins for children with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia is one of the most common inherited metabolic diseases; the average worldwide prevalence of heterozygous familial hypercholesterolemia is at least 1 in 500. Diagnosis of familial hypercholesterolemia in children is based on highly elevated low-density lipoprotein (LDL) cholesterol level or DNA-based analysis, or both. Coronary atherosclerosis has been detected in men with heterozygous familial hypercholesterolemia as young as 17 years old and in women with heterozygous familial hypercholesterolemia at 25 years old. Since the clinical complications of atherosclerosis occur prematurely, especially in men, lifelong hypolipidemic measures, started in childhood, are needed to reduce the risk of cardiovascular disease. In children with familial hypercholesterolemia, diet is as yet the cornerstone of treatment. Anion exchange resins, such as cholestyramine and colestipol, have also been found to be effective, but are poorly tolerated. Since the 1990s statin studies have been carried out among children with familial hypercholesterolemia (aged 7 to 17 years). Statins greatly reduced their serum LDL cholesterol levels. Even though statins seem to be safe and well-tolerated in children, their long-term safety in this age group is not firmly established.

OBJECTIVES

To assess the effectiveness and safety of statins in children with familial hypercholesterolemia.

SEARCH METHODS

Relevant studies were identified from the Group's Inborn Errors and Metabolism Trials Register and Medline.Date of most recent search: 14 October 2013.

SELECTION CRITERIA

Randomized and controlled clinical studies including participants up to 18 years old, comparing a statin to placebo or to diet alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion and extracted data.

MAIN RESULTS

We found 21 potentially eligible studies, of which we included eight randomized placebo-controlled studies (1074 participants). In general, the intervention and follow-up time was short (median 24 weeks; range from six weeks to two years). Statins reduced the mean LDL cholesterol concentration at all time points. Serum aspartate and alanine aminotransferase, as well as creatinine kinase concentrations, did not differ between treated and placebo groups at any time point. The risks of myopathy and clinical adverse events were very low and also similar in both groups. In one study simvastatin was shown to improve flow-mediated dilatation of the brachial artery, and in another study treatment with pravastatin for two years induced a significant regression in carotid intima media thickness.

AUTHORS' CONCLUSIONS

Statin treatment is an efficient lipid-lowering therapy in children with familial hypercholesterolemia. No significant safety issues were identified. Statin treatment seems to be safe in the short term, but long-term safety is unknown. Children treated with statins should be carefully monitored and followed up by their pediatricians or physicians into adulthood. Large long-term randomized controlled trials are needed to establish the long-term safety issues of statins.

Non-cardiovascular effects associated with statins

Statins form the pharmacologic cornerstone of the primary and secondary prevention of atherosclerotic cardiovascular disease. In addition to beneficial cardiovascular effects, statins seem to have multiple non-cardiovascular effects. Although early concerns about statin induced hepatotoxicity and cancer have subsided owing to reassuring evidence, two of the most common concerns that clinicians have are myopathy and diabetes. Randomized controlled trials suggest that statins are associated with a modest increase in the risk of myositis but not the risk of myalgia. Severe myopathy (rhabdomyolysis) is rare and often linked to a statin regimen that is no longer recommended (simvastatin 80 mg). Randomized controlled trials and meta-analyses suggest an increase in the risk of diabetes with statins, particularly with higher intensity regimens in people with two or more components of the metabolic syndrome. Other non-cardiovascular effects covered in this review are contrast induced nephropathy, cognition, cataracts, erectile dysfunction, and venous thromboembolism. Currently, systematic reviews and clinical practice guidelines indicate that the cardiovascular benefits of statins generally outweigh non-cardiovascular harms in patients above a certain threshold of cardiovascular risk. Literature is also accumulating on the potential non-cardiovascular benefits of statins, which could lead to novel applications of this class of drug in the future.

Statin use and cataract surgery: a nationwide retrospective cohort study in elderly ethnic Chinese patients

BACKGROUND

Since a report of lenticular opacities in dogs treated with high dosages of statins, the debate on the relationship between statin therapy and cataracts has not reached a conclusion.

OBJECTIVE

The aim of this study was to evaluate the association between statin therapy and the risk of cataract surgery in an elderly ethnic Chinese population using time-dependent analysis to minimize immortal time bias.

METHODS

A retrospective cohort study using the Longitudinal Health Insurance Database 2005 randomly sampled from the National Health Insurance Research Database, Taiwan, was conducted. A total of 50,165 adults aged between 65 and 90 years in 1998 without records of statin therapy or diagnosis of cataracts between July 1997 and December 1997 were included in the analysis. The first record of lens extraction within the follow-up period (1998-2009) was set as the study endpoint. A propensity score was derived using a logistic regression model to model the receipt of statin therapy as a function of the baseline characteristics for every subject. We used the time-dependent Cox regression model to test the relative hazard of undergoing cataract surgery between statin users and non-users, while use of statins was treated as a time-dependent variable, controlling for baseline age and individual propensity score.

RESULTS

Of the 50,165 enrolled subjects, 17,670 individuals with an incident lens extraction were identified during a median follow-up of 10.7 years. The incidence of cataract surgery was 49.7/1,000 person-years in the statin-using period compared with 38.5/1,000 person-years in the statin-non-using period. The adjusted hazard ratio of cataract surgery was 1.20 (95 % CI 1.14-1.27; P < 0.001) in statin users compared with statin non-users.

CONCLUSION

Statin therapy was associated with a modestly increased risk of cataract surgery. We suggest regular checks for lens opacity in statin users.

Prevention of cataracts by statins: a meta-analysis

BACKGROUND

Current data indicate a persisting concern about possible cataractogenecity of statins.

OBJECTIVE

To perform a meta-analysis of studies pertaining to statins and cataract.

METHODS

We identified 363 records by a systematic search of the MedLine, Web of Knowledge, Cochrane database, and ClinicalTrials.gov. After exclusion of duplicates, studies without cataract as an outcome, reviews, and animal or basic science studies, we analyzed 14 studies. Two end points were examined: clinical cataract (requiring extraction or reported by the patient) and lens opacities discovered by slit-lamp examination.

RESULTS

Using random effects meta-analysis, a statistically significant decrease in cataracts with statins was observed among studies examining clinical cataract (odds ratio [OR] 0.81, 95% confidence interval [CI] 0.71-0.93, P = .0022). Absolute risk reduction was 1.4% ± 0.015%, 95% CI 1.1%-1.7%, P < .0001, corresponding to 71, 95% CI 59-91, number needed to treat. The effect was larger for the harder end point of cataract extraction (OR 0.66, 95% CI 0.61-0.71, P < .0001). Metaregression indicated an increase in benefit with longer duration of statin use with OR varying from 0.54 for a treatment duration of 14 years to 0.95 for a treatment duration of 6 months. Older age was associated with lower benefit (OR 1.03 for persons in their 70s to OR 0.49 for persons in their 40s), and there were no differences by gender. Several sensitivity analyses confirmed the results. Limitations of this analysis include the combination of randomized and observational studies and imprecise ascertainment of exposure and incomplete adjustment for confounders in several observational studies.

CONCLUSION

This meta-analysis indicates a clinically relevant protective effect of statins in preventing cataracts. The effect is more pronounced in younger patients and with longer duration of follow-up, while there is no difference by gender.

Age-related cataract is associated with type 2 diabetes and statin use

PURPOSE

Diabetes has been shown to be a risk factor for age-related (AR) cataract. As statins (HMG-CoA reductase inhibitors) are now commonly prescribed for patients with type 2 diabetes, their impact on AR cataract prevalence should be considered. This study determines associations between AR cataract, type 2 diabetes, and reported statin use in a large optometric clinic population.

METHODS

In all, 6397 patient files (ages <1-93 years) were reviewed. Overall prevalence of statin use was calculated for patients with type 2 diabetes (n = 452) and without diabetes (n = 5884). Multivariable logistic regression analysis for AR cataract was performed controlling for patient sex, smoking, high blood pressure, type 2 diabetes, and statin use.

RESULTS

The prevalence of statin use (in patients aged >38 years) was 56% for those with type 2 diabetes and 16% for those without diabetes. Type 2 diabetes was significantly associated with nuclear sclerosis (OR = 1.62, 1.14-2.29) and cortical cataract (OR = 1.37, 1.02-1.83). Statin use was associated with nuclear sclerosis (OR = 1.48, 1.09-2.00) and posterior subcapsular cataract (OR = 1.48, 1.07-2.04). The 50% probability of cataract in statin users occurred at age 51.7 and 54.9 years in patients with type 2 diabetes and without diabetes, respectively. In non-statin users, it was significantly later at age 55.1 and 57.3 years for patients with type 2 diabetes and without diabetes, respectively (p < 0.001).

CONCLUSIONS

In this population, statin use was substantially higher in patients with type 2 diabetes and was associated with AR cataracts. Further long-term study is warranted to recommend monitoring of crystalline lenses in patients with type 2 diabetes benefiting from statins.

Cardiovascular event reduction and adverse events among subjects attaining low-density lipoprotein cholesterol <50 mg/dl with rosuvastatin. The JUPITER trial (Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin)

OBJECTIVES

The purpose of this study was to assess the impact on cardiovascular and adverse events of attaining low-density lipoprotein cholesterol (LDL-C) levels <50 mg/dl with rosuvastatin in apparently healthy adults in the JUPITER (Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin) trial.

BACKGROUND

The safety and magnitude of cardiovascular risk reduction conferred by treatment to LDL-C levels below current recommended targets remain uncertain.

METHODS

A cohort of 17,802 apparently healthy men and women with high-sensitivity C-reactive protein ≥2 mg/l and LDL-C <130 mg/dl were randomly allocated to rosuvastatin 20 mg daily or placebo, and followed up for all-cause mortality, major cardiovascular events, and adverse events. In a post-hoc analysis, participants allocated to rosuvastatin were categorized as to whether or not they had a follow-up LDL-C level <50 mg/dl.

RESULTS

During a median follow-up of 2 years (range up to 5 years), rates of the primary trial endpoint were 1.18, 0.86, and 0.44 per 100 person-years in the placebo group (n = 8,150) and rosuvastatin groups without LDL-C <50 mg/dl (n = 4,000) or with LDL-C <50 mg/dl (n = 4,154), respectively (fully-adjusted hazard ratio: 0.76; 95% confidence interval: 0.57 to 1.00 for subjects with no LDL-C <50 mg/dl vs. placebo and 0.35, 95% confidence interval: 0.25 to 0.49 for subjects attaining LDL-C <50 mg/dl; p for trend <0.0001). For all-cause mortality, corresponding event rates were 0.67, 0.65, and 0.39 (p for trend = 0.004). Rates of myalgia, muscle weakness, neuropsychiatric conditions, cancer, and diabetes mellitus were not significantly different among rosuvastatin-allocated participants with and without LDL-C <50 mg/dl.

CONCLUSIONS

Among adults with LDL-C <130 mg/dl and high-sensitivity C-reactive protein ≥2 mg/l, rosuvastatin-allocated participants attaining LDL-C <50 mg/dl had a lower risk of cardiovascular events without a systematic increase in reported adverse events.

Role of HMG-CoA reductase inhibitors with curative radiotherapy in men with prostate cancer

Brachytherapy and external beam radiotherapy are effective and commonly used treatment modalities in men with localized prostate cancer. In this review, we explore the role of radiation therapy in the curative management of prostate cancer, including the use of conformal therapeutic techniques to allow for the escalation of radiation doses to tumor, along with the use of combined radiation and hormonal therapy to enhance disease outcomes in men with aggressive disease. We also review the possible anticancer role of HMG-CoA reductase inhibiting agents (statins) in men with prostate cancer. Laboratory evidence suggests that statins may have antineoplastic effects when used alone and may sensitize cells to radiation therapy when given in combination. We explore the biologic basis for an anticancer effect and the clinical evidence suggesting statins may aid in improving outcomes with radiation therapy for localized prostate cancer.

The safety of statins in clinical practice

Statins are effective cholesterol-lowering drugs that reduce the risk of cardiovascular disease events (heart attacks, strokes, and the need for arterial revascularisation). Adverse effects from some statins on muscle, such as myopathy and rhabdomyolysis, are rare at standard doses, and on the liver, in increasing levels of transaminases, are unusual. Myopathy--muscle pain or weakness with blood creatine kinase levels more than ten times the upper limit of the normal range--typically occurs in fewer than one in 10,000 patients on standard statin doses. However, this risk varies between statins, and increases with use of higher doses and interacting drugs. Rhabdomyolysis is a rarer and more severe form of myopathy, with myoglobin release into the circulation and risk of renal failure. Stopping statin use reverses these side-effects, usually leading to a full recovery. Asymptomatic increases in concentrations of liver transaminases are recorded with all statins, but are not clearly associated with an increased risk of liver disease. For most people, statins are safe and well-tolerated, and their widespread use has the potential to have a major effect on the global burden of cardiovascular disease.

Ophthalmic drug delivery considerations at the cellular level: drug-metabolising enzymes and transporters

Ophthalmic drugs typically achieve < 10% ocular bioavailability. A drug applied to the surface of the eye may cross ocular-blood barriers where it may encounter metabolising enzymes and cellular transporters before it distributes to the site of action. Characterisation of ocular enzyme systems and cellular transporters and their respective substrate selectivity have provided new insight into the roles these proteins may play in ocular drug delivery and distribution. Altered metabolism and transport have been proposed to contribute to a number of ocular disease processes including inflammation, glaucoma, cataract, dry eye and neurodegeneration. As ocular enzyme and transport systems are better characterised, their properties become an integral consideration in drug design and development.

Lovastatin and beyond: the history of the HMG-CoA reductase inhibitors

In the 1950s and 1960s, it became apparent that elevated concentrations of plasma cholesterol were a major risk factor for the development of coronary heart disease, which led to the search for drugs that could reduce plasma cholesterol. One possibility was to reduce cholesterol biosynthesis, and the rate-limiting enzyme in the cholesterol biosynthetic pathway, 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, was a natural target. Here, I describe the discovery and development of lovastatin--the first approved inhibitor of HMG-CoA reductase--and the clinical trials that have provided the evidence for the ability of drugs in this class to reduce the morbidity and mortality associated with cardiovascular disease.

[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.

3 year simvastatin treatment and lens nuclear back scattering

AIM

To determine if 3 year treatment of hypercholesterolaemia with simvastatin causes an increase of lens nuclear back scattering.

METHODS

160 patients with hypercholesterolaemia in the Scandinavian Simvastatin Survival Study (4S) were followed for 3 years. Half (80) of the patients took simvastatin and half (80) received placebo. The lens was photographed with a Topcon SL-45 slit lamp camera at the beginning and at 1 year intervals. A common lens nuclear area was used for measuring lens nuclear back scattering.

RESULTS

Nuclear back scattering increased with age and there was more pronounced scattering in women than in men. Lens nuclear back scattering did not differ significantly between the simvastatin and placebo groups, but the power was low (0.2). Lens nuclear back scattering increased during the study period independently of baseline back scattering, age, and sex for both groups.

CONCLUSION

Although no significant difference was found between the simvastatin and placebo groups, the currently available data are insufficient for exclusion of the possibility that taking simvastatin during a 3 year period increases nuclear back scattering. However, a possible minor increase of nuclear back scattering is clinically irrelevant considering known beneficial effects of simvastatin on coronary heart disease.

Metabolism and drug interactions of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in transplant patients: are the statins mechanistically similar?

3-Hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.88) inhibitors are the most effective drugs to lower cholesterol in transplant patients. However, immunosuppressants and several other drugs used after organ transplantation are cytochrome P4503A (CYP3A, EC 1.14.14.1) substrates. Pharmacokinetic interaction with some of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, specifically lovastatin and simvastatin, leads to an increased incidence of muscle skeletal toxicity in transplant patients. It is our objective to review the role of drug metabolism and drug interactions of lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, and cerivastatin. In the treatment of transplant patients, from a drug interaction perspective, pravastatin, which is not significantly metabolized by CYP enzymes, and fluvastatin, presumably a CYP2C9 substrate, compare favorably with the other statins for which the major metabolic pathways are catalyzed by CYP3A.