Tendinous disorders attributed to statins: a study on ninety-six spontaneous reports in the period 1990-2005 and review of the literature

Efficacy and safety of rosuvastatin in the management of dyslipidemia

Rosuvastatin is a synthetic statin that represents an advance in the pharmacologic and clinical properties of statins. Relative to other statins, rosuvastatin possesses a greater number of binding interactions with HMG-CoA reductase and has a high affinity for the active site of the enzyme. As with other statins, serious adverse effects with rosuvastatin therapy are uncommon and primarily involve effects on the liver and skeletal muscle. The risk increases with increasing dosages and coadministration with other drugs interacting with the same metabolic pathway. The degree of LDL reduction is important to achieve the treatment goals suggested by international guidelines. Among the most potent statins, rosuvastatin is capable of getting the majority of patients to their LDL cholesterol goals. In addition, rosuvastatin has been found effective in reducing small-dense LDL, C-reactive protein and in increasing HDL cholesterol levels. Controlled clinical trials using vascular end-points have been performed. In particular, a study demonstrated that rosuvastatin therapy could slow progression and/or cause regression of carotid intima-media thickness over 2 years in middle-aged individuals with a low Framingham risk score (FRS) and mild to moderate subclinical atherosclerosis. A primary prevention study (JUPITER) was stopped before the programmed end of the study, because of excess benefit for high-risk individuals receiving rosuvastatin treatment. It is suggested that pronounced LDL reduction, in association with significant HDL cholesterol increase, are the bases of a marked preventive action of rosuvastatin. The results from JUPITER support the use of rosuvastatin for primary cardiovascular prevention, in overweight men and women, with near to normal LDL cholesterol and high CRP. There is now evidence of benefit from rosuvastatin treatment for a wide segment of the general population at intermediate cardiovascular risk. In absolute numbers, this segment represents the main source of cardiovascular events: on the basis of JUPITER results, it is expected that treatment target and potential candidates to statin therapy will be revaluated and redefined.

Suspected statin-induced respiratory muscle myopathy during long-term inspiratory muscle training in a patient with diaphragmatic paralysis

BACKGROUND AND PURPOSE

Abnormal lipids are associated with the development of coronary heart disease; for this reason, lipid-lowering agents have become a standard of care. The purposes of this case report are: (1) to highlight the association of impaired inspiratory muscle performance (IMP) with statin therapy and (2) to describe potentially useful methods of examining and treating people with known or suspected statin-induced skeletal myopathies (SISMs).

CASE DESCRIPTION

The patient had breathlessness on exertion and a restrictive lung disorder from a right hemidiaphragmatic paralysis, for which he was prescribed high-intensity inspiratory muscle training (IMT). He had a secondary diagnosis of hyperlipidemia, which was treated with 40 mg of simvastatin after 5(1/2) months of IMT.

OUTCOMES

The improvements in IMP, symptoms, and functional status obtained from almost 6 months of high-intensity IMT were lost after the commencement of simvastatin. However, 3 weeks after termination of simvastatin combined with high-intensity IMT, the patient's IMP, symptoms, and functional status exceeded pre-statin levels.

DISCUSSION

This case report suggests that high-intensity IMT can be used effectively in a patient with impaired diaphragmatic function and during recovery from a respiratory SISM. The marked reduction in IMP and inability to perform IMT resolved with the cessation of statin therapy. The case report also highlights the potential effects of SISMs in all skeletal muscle groups. The clinical implications of this case report include the potential role of physical therapy in monitoring and possibly facilitating the spontaneous recovery of an SISM, as well as the need to investigate the IMP of a person with dyspnea and fatigue who is taking a statin.

Involvement of organic anion transporting polypeptides in the toxicity of hydrophilic pravastatin and lipophilic fluvastatin in rat skeletal myofibres

BACKGROUND AND PURPOSE

There is a discrepancy in the adverse effect of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, statins between the clinical reports and the studies using skeletal muscle cell models. In the clinical reports, both hydrophilic and lipophilic statins induce myotoxicity, whereas in in vitro experiments using cell lines of myoblasts, lipophilic, but not hydrophilic, statins exert myotoxicity. We investigated the cause of this discrepancy.

EXPERIMENTAL APPROACH

Skeletal myofibres, fibroblasts and satellite cells were isolated from rat flexor digitorum brevis (FDB) muscles. Using these primary cultured cells as well as the L6 myoblast cell line, we compared the toxicity of hydrophilic pravastatin and lipophilic fluvastatin. The mRNA expression levels of possible drug transporters for statins were also examined in these cells using reverse transcriptase-PCR.

KEY RESULTS

In the skeletal myofibres, both pravastatin and fluvastatin induced vacuolation and cell death, whereas in the mononuclear cells only fluvastatin, but not pravastatin, was toxic. mRNA of the organic anion transporting polypeptides (Oatp) 1a4 and Oatp2b1 were expressed in the skeletal myofibres, but not in mononucleate cells. Estrone-3-sulphate, a substrate for Oatps, attenuated the effects of pravastatin and fluvastatin in skeletal myofibres; p-aminohippuric acid, a substrate for the organic anion transporters (Oats), but not Oatps, failed to do so.

CONCLUSIONS AND IMPLICATIONS

The statin transporters Oatp1a4 and Oatp2b1 are expressed in rat skeletal myofibres, but not in satellite cells, fibroblasts or in L6 myoblasts. This is probably why hydrophilic pravastatin affects skeletal muscle, but not skeletal myoblasts.

Statin adverse effects : a review of the literature and evidence for a mitochondrial mechanism

HMG-CoA reductase inhibitors (statins) are a widely used class of drug, and like all medications, have potential for adverse effects (AEs). Here we review the statin AE literature, first focusing on muscle AEs as the most reported problem both in the literature and by patients. Evidence regarding the statin muscle AE mechanism, dose effect, drug interactions, and genetic predisposition is examined. We hypothesize, and provide evidence, that the demonstrated mitochondrial mechanisms for muscle AEs have implications to other nonmuscle AEs in patients treated with statins. In meta-analyses of randomized controlled trials (RCTs), muscle AEs are more frequent with statins than with placebo. A number of manifestations of muscle AEs have been reported, with rhabdomyolysis the most feared. AEs are dose dependent, and risk is amplified by drug interactions that functionally increase statin potency, often through inhibition of the cytochrome P450 3A4 system. An array of additional risk factors for statin AEs are those that amplify (or reflect) mitochondrial or metabolic vulnerability, such as metabolic syndrome factors, thyroid disease, and genetic mutations linked to mitochondrial dysfunction. Converging evidence supports a mitochondrial foundation for muscle AEs associated with statins, and both theoretical and empirical considerations suggest that mitochondrial dysfunction may also underlie many nonmuscle statin AEs. Evidence from RCTs and studies of other designs indicates existence of additional statin-associated AEs, such as cognitive loss, neuropathy, pancreatic and hepatic dysfunction, and sexual dysfunction. Physician awareness of statin AEs is reportedly low even for the AEs most widely reported by patients. Awareness and vigilance for AEs should be maintained to enable informed treatment decisions, treatment modification if appropriate, improved quality of patient care, and reduced patient morbidity.