Disorder resembling Guillain-Barré syndrome on initiation of statin therapy

Impact of Atorvastatin on Skeletal Muscle Mitochondrial Activity, Locomotion and Axonal Excitability-Evidence from ApoE-/- Mice

The cardiovascular benefit of statins is well established. However, only 20% of high-risk patients remain adequately adherent after 5 years of treatment. Among reasons for discontinuation, statin associated-muscle pain symptoms are the most prevalent. Aim of the present study was to evaluate the impact of high dose atorvastatin on skeletal muscle mitochondrial activity, aerobic and anaerobic exercise, and axonal excitability in a murine model of atherosclerosis. ApoE^-/- mice were fed 12 weeks a high-fat high-cholesterol diet alone or containing atorvastatin (40 mg/Kg/day). Outcomes were the evaluation of muscle mitochondrial functionality, locomotion, grip test, and axonal excitability (compound action potential recording analysis of Aα motor propioceptive, Aβ mechanoceptive and C nociceptive fibres). Atorvastatin led to a reduction in muscle mitochondrial biogenesis and mitochondrial ATP production. It did not affect muscular strength but led to a time-dependent motor impairment. Atorvastatin altered the responsiveness of mechanoceptive and nociceptive fibres, respectively, the Aβ and C fibres. These findings point out to a mild sensitization on mechanical, tactile and pain sensitivity. In conclusion, although the prevalence of muscular side effects from statins may be overestimated, understanding of the underlying mechanisms can help improve the therapeutic approach and reassure adherence in patients needing-to-be-treated.

Pathophysiology, prevention, and treatment of beriberi after gastric surgery

Beriberi is a nutritional complication of gastric surgery, caused by deficiency of vitamin B₁, or thiamine. Thiamine deficiency leads to impaired glucose metabolism, decreased delivery of oxygen by red blood cells, cardiac dysfunction, failure of neurotransmission, and neuronal death. This review describes the history and pathophysiology of beriberi as well as the relationship between beriberi and nutritional deficiencies after gastric surgery. A literature review of the history and pathophysiology of beriberi and the risk factors for thiamine deficiency, particularly after gastric resection or bariatric surgery, was performed. Recommendations for nutritional follow-up post gastric surgery are based on current national guidelines. Patients may have subclinical thiamine deficiency after upper gastrointestinal surgery, and thus beriberi may be precipitated by acute illness such as sepsis or poor dietary intake. This may occur very soon or many years after gastrectomy or bariatric surgery, even in apparently well-nourished patients. Prompt recognition and administration of supplemental thiamine can decrease morbidity and mortality in patients with beriberi. Dietary education post surgery and long-term follow-up to determine nutritional status, including vitamin and mineral assessment, is recommended for patients who undergo gastric surgery.

Statins and polyneuropathy revisited: case-control study in Denmark, 1999-2013

AIM

In a previous study, we found a positive association between statin use and polyneuropathy risk. Other studies reported equivocal results. The present study aimed to confirm our findings with a design similar to that used in our previous study but with a larger data set.

METHODS

We searched medical registry data to identify patients diagnosed with incident polyneuropathy of no known cause (idiopathic polyneuropathy) between 1999 and 2013; we verified diagnoses through medical records. For each case, we recruited 20 general population controls with no previous history of polyneuropathy. Controls were matched to their respective case for age and gender. We ascertained the prior statin use of cases and controls through a prescription registry. Based on this information, exposure to statins was categorized into 'ever use' or 'never use'. Ever use of statins was classified by how recently they had been used ('current use' or 'past use'); current use was further classified into long-term use (5+ years) and high- or low-intensity use. We used conditional logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) to examine associations between polyneuropathy and statin use.

RESULTS

We included 370 validated cases and 7400 controls. Ever use of statins was not associated with an elevated risk of polyneuropathy (OR 1.14, 95% CI 0.84, 1.54). Similarly, we found no associations between polyneuropathy risk and current use (OR 1.11, 95% CI 0.79, 1.53), long-term use (OR 1.13, 95% CI 0.66, 1.92) or high-intensity statin use (OR 1.05, 95% CI 0.59, 1.84).

CONCLUSION

Statin use was not associated with an increased risk of idiopathic polyneuropathy.

A reappraisal of the risks and benefits of treating to target with cholesterol lowering drugs

Atherosclerotic cardiovascular disease (CVD) is the number one cause of death globally, and lipid modification, particularly lowering of low density lipoprotein cholesterol (LDLc), is one of the cornerstones of prevention and treatment. However, even after lowering of LDLc to conventional goals, a sizeable number of patients continue to suffer cardiovascular events. More aggressive lowering of LDLc and optimization of other lipid parameters like triglycerides (TG) and high density lipoprotein cholesterol (HDLc) have been proposed as two potential strategies to address this residual risk. These strategies entail use of maximal doses of highly potent HMG CoA reductase inhibitors (statins) and combination therapy with other lipid modifying agents. Though statins in general are fairly well tolerated, adverse events like myopathy are dose related. There are further risks with combination therapy. In this article, we review the adverse effects of lipid modifying agents used alone and in combination and weigh these effects against the evidence demonstrating their efficacy in reducing cardiovascular events, cardiovascular mortality, and all cause mortality. For patients with established CVD, statins are the only group of drugs that have shown consistent reductions in hard outcomes. Though more aggressive lipid lowering with high dose potent statins can reduce rates of non fatal events and need for interventions, the incremental mortality benefits remain unclear, and their use is associated with a higher rate of drug related adverse effects. Myopathy and renal events have been a significant concern with the use of high potency statin drugs, in particular simvastatin and rosuvastatin. For patients who have not reached target LDL levels or have residual lipid abnormalities on maximal doses of statins, the addition of other agents has not been shown to improve clinical outcomes and carries an increased risk of adverse events. The clinical benefits of drugs to raise HDLc remain unproven. In patients without known cardiovascular disease, there is conflicting evidence as to the benefits of aggressive pursuit of numerical lipid targets, particularly with respect to all cause mortality. Certainly, in statin intolerant patients, alternative agents with a low side effect profile are desirable. Bile acid sequestrants are an effective and safe choice for decreasing LDLc, and omega-3 fatty acids are safe agents to decrease TG. There remains an obvious need to design and carry out large scale studies to help determine which agents, when combined with statins, have the greatest benefit on cardiovascular disease with the least added risk. These studies should be designed to assess the impact on clinical outcomes rather than surrogate endpoints, and require a comprehensive assessment and reporting of safety outcomes.

Drug-induced neuropathies

Although drug-induced neuropathies account for only 2-4% of referrals, their identification is important. Numerically, chemotherapy and antiretroviral drugs are the most important worldwide. Research is currently focused on elucidating pathogenic mechanisms and the earliest presymptomatic changes using neurophysiological and pharmacogenetic techniques in order to avoid the drug or make dosage changes before irreversible damage occurs. Chemoprotectants against chemotherapy-induced neuropathy are also an active area of research. This chapter focuses on the pathophysiology of drug-induced neuropathies in general, followed by detailed reviews of neuropathy due to; newer compounds such as TNF (tumor necrosis factor) α antagonists and antibiotics such as linezolid; chemotherapeutic agents, old and new, where significant progress has been made; antiretroviral drugs; and amiodarone, which is unusual in that it causes a demyelinating neuropathy. The controversial issue of statin-induced neuropathy is also reviewed.

Severe statin-induced rhabdomyolysis mimicking Guillain-Barré syndrome in four patients with diabetes mellitus treated with fusidic acid

BACKGROUND

An interaction between fusidic acid and HMG coenzyme A reductase inhibitors (statins), resulting in rhabdomyolysis, has been described. Pain and mild weakness are common presenting symptoms.

CASE REPORT

We report four patients with Type 2 diabetes prescribed long-term statin treatment who, following treatment with fusidic acid, presented atypically with painless, severe flaccid paralysis suggestive of Guillain-Barré syndrome. This, together with nerve conduction studies consistent with Guillain-Barré syndrome, resulted in the delayed recognition of rhabdomyolysis in these cases.

CONCLUSIONS

The addition of fusidic acid can precipitate rhabdomyolysis in patients with diabetes already taking a statin. This can present with rapidly progressive weakness resembling Guillain-Barré syndrome. We recommend that creatine kinase is checked in patients with diabetes on statin therapy who present with profound weakness and routinely in those commenced on prolonged courses of fusidic acid.

Effect of statins on a wide range of health outcomes: a cohort study validated by comparison with randomized trials

AIMS

To assess the effect of statins on a range of health outcomes.

METHODS

We undertook a population-based cohort study to assess the effect of statins on a range of health outcomes using a propensity score-based method to control for differences between people prescribed and not prescribed statins. We validated our design by comparing our results for vascular outcomes with the effects established in large randomized trials. The study was based on the United Kingdom Health Improvement Network database that includes the computerized medical records of over four and a half million patients.

RESULTS

People who initiated treatment with a statin (n = 129,288) were compared with a matched sample of 600,241 people who did not initiate treatment, with a median follow-up period of 4.4 years. Statin use was not associated with an effect on a wide range of outcomes, including infections, fractures, venous thromboembolism, gastrointestinal haemorrhage, or on specific eye, neurological or autoimmune diseases. A protective effect against dementia was observed (hazard ratio 0.80, 99% confidence interval 0.68, 0.95). There was no effect on the risk of cancer even after > or =8 years of follow-up. The effect sizes for statins on vascular end-points and mortality were comparable to those observed in large randomized trials, suggesting bias and confounding had been well controlled for.

CONCLUSIONS

We found little evidence to support wide-ranging effects of statins on health outcomes beyond their established beneficial effect on vascular disease.

Dixièmes Journées des Maladies du Système Nerveux Périphérique Neuropathies aux statines, mythe ou réalité?

BACKGROUND

Statins are lipid-lowering drugs widely used in the world. They are effective and safe in the treatment and in the primary and secondary prevention of cerebrovascular and cardiovascular diseases. Besides they are known for their muscular side-effects. It has been suggested that they also have a toxic effect on the peripheral nervous system.

STATE OF ART

Case reports and retrospective studies emphasize the possibility that statins can induce peripheral nerves side-effects. A single prospective study contradicts this hypothesis. Statins are hydroxymethyl glutaryl coenzyme A reductase (HMGCoA reductase) inhibitors, this action is responsible for the lipid-lowering effect but can also explain the nervous toxicity. Statins interfere with cholesterol synthesis that may alter myelin and nerve membrane function and they prevent mitochondrial respiratory chain enzyme synthesis which may disturb neuron energy use.

CONCLUSIONS

It can be considered that statins have an insignificant toxicity on peripheral nerves. The relevance of their prescription must be however well evaluated and treated patients must be closely followed.

Statin-associated adverse effects beyond muscle and liver toxicity

Randomized controlled trials with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have consistently demonstrated significant reductions in cardiovascular morbidity and mortality. Statins are currently the most widely used drugs in many countries. The most important adverse effects are associated with muscle and liver toxicity. However, with increased use and dose of statins and their over-the-counter availability in some countries more cases of other rare side effects may be seen in clinical practice. In the present article we review the literature concerning the statin-related adverse effects other than muscle and liver injury and we provide insight into their clinical relevance and possible underlying mechanisms.

Statin safety: an overview and assessment of the data--2005

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statin drugs, have been studied in numerous controlled human research trials involving hundreds of thousands of study participants. Statins have been prescribed for millions of patients. Based on this vast research and clinical experience, statins have been shown to improve lipid blood levels and reduce atherosclerotic coronary artery disease (CAD) risk, resulting in reduced CAD morbidity and mortality, and in several studies, reduced overall ("all-cause") mortality. From a safety perspective, both research trial evidence and clinical practice experience have demonstrated that statins are generally well tolerated. However, as with all pharmaceuticals, safety considerations exist with both monotherapy and combination statin therapy, mainly involving potential adverse effects on muscle, liver, kidney, and the nervous system. The evidence supporting statin-related potential adverse experiences on these organ systems is sometimes strong and based on clear clinical trial evidence (such as the increased risk of muscle enzyme elevation with higher statin doses). The evidence is at other times more speculative, being based on case reports and inconclusive clinical trial data (such as possible favorable or unfavorable effects of statins on cognition). Because the use of statins is so widespread, it is useful for the clinician to understand statin safety issues and the level of available evidence supporting the contention that various adverse effects are caused by statins. This review presents an assessment of statin safety based on an overview of the current statin safety data and their clinical implications.

Statins: panacea for sepsis?

Sepsis occurs when the immune system responds to a localised infection at a systemic level, thereby causing tissue damage and organ dysfunction. Statins have proven health benefits in many diseases involving vascular inflammation and injury. Recent animal data suggest that the administration of a statin before a sepsis-inducing insult reduces morbidity and improves survival. The immunomodulatory and anti-inflammatory effects of statins, collectively referred to as pleiotropic effects, lend biological plausibility to such findings. Limited human data hint at reduced mortality rates in bacteraemic patients, and a reduced risk of sepsis in patients with bacterial infections concurrently taking statins. These lines of evidence point to a potential new treatment and prevention modality for sepsis. The stage is set for randomised controlled clinical trials that will determine whether statins represent a safe and beneficial treatment in critically ill, septic patients and whether statins are effective at preventing sepsis in high-risk clinical settings.

Toxic neuropathy

PURPOSE OF REVIEW

This paper examines recent research on toxic neuropathy and potential therapeutic developments. It also summarizes reports of new agents reported to cause peripheral neuropathy.

RECENT FINDINGS

Gene therapy with vasoactive endothelial growth factor, neurotrophic substances such as nerve growth factor and neurotrophin-3 are reported to reverse or protect against neurotoxicity in animal models. The neuroprotective effects of more established therapeutic agents like vitamin E, tacrolimus (FK 506) and erythropoietin hold promise for the immediate future. Cisplatin and high-dose pyridoxine are used more frequently to produce robust models of peripheral neuropathy in animals. Statins do appear to cause peripheral neuropathy. The incidence is low, however, and compared to its benefits in terms of cardiovascular protection, relatively innocuous. The profile of thalidomide neuropathy is becoming clearer as the indications for this drug increases. The incidence of thalidomide neuropathy is high, up to three quarters in some series, and although the information on dose dependency is variable, lower cumulative doses appear to be less toxic. Like thalidomide bortezomib, a novel proteosome inhibitor, is reportedly effective in the treatment of multiple myeloma and is associated with peripheral neuropathy. Oxaliplatin and epothilone are emerging anticancer drugs with neurotoxic potential. Similarly, leflunomide, a new disease modifying-agent approved for the treatment of rheumatoid arthritis, is reported to cause neuropathy.

SUMMARY

The study of toxic neuropathy is not only enhancing our knowledge of the mechanisms of neurotoxicity but also the neurobiology of peripheral neuropathy in general; and is likely to reveal avenues for therapeutics.

Focal seizures after treatment with fluvastatin in a patient with a history of catastrophic antiphospholipid syndrome

We report a 36-year-old woman with the occurrence of painful focal seizures of her left hand and the left leg. She also had focal motor seizures at the left corner of her mouth. The duration and frequency of the episodes increased over four days from a few seconds once a day to frequent intervals lasting more than four hours at a time. The symptoms appeared one day after start of the treatment with fluvastatin (40 mg) administered in order to diminish the endothelial activation induced by antiphospholipid antibodies (aPL). The patient suffered from severe manifestations of the antiphospholipid syndrome (APS) including Catastrophic Antiphospholipid Syndrome (CAPS, Asherson's syndrome). In this case a single 40 mg dose of oral fluvastatin was linked to seizures. After discontinuation of this treatment, the seizures immediately disappeared and the patient fully recovered without evidence of permanent neurological damage. This data links statins to seizures in patients with compromised blood brain barrier such as APS.