Statin-associated Myopathy

Management of Myopathy

For most patients, myopathy symptoms induced by statin therapy resolve relatively quickly; however, the results of the PRIMO study showed that it may take up to 2 months for resolution of symptoms.^[4] There is limited evidence regarding the treatment of statin-associated myopathy. While myopathy caused by statins can be mild and can be reversed when the medication is discontinued, it may present as rhabdomyolysis or severe muscle damage. The mainstay of myopathy management is cessation of therapy; however, it is prudent for clinicians to rule out other conditions that can cause myopathy and/or CK elevations, such as hypothyroidism, overt physical activity, and alcohol abuse.^[28] Patients who present with clinically significant rhabdomyolysis require hospitalization and IV hydration to prevent renal damage.^[3]

Once the patient's muscle symptoms have resolved, clinicians have several options to treat that patient's dyslipidemia, including the use of a lower dose of the same statin, initiation of a different statin, and/or utilization of nonstatin lipid-lowering agents.^[3] The decision to resume statin therapy should be carefully considered in those patients at high risk of cardiovascular disease.^[6] Recently, studies have evaluated safety and efficacy when switching from one statin to another. These studies have shown that in patients with a prior statin intolerance, the use of another statin is both well tolerated and efficacious.^[30,31] If the patient is rechallenged with statin therapy and the target LDL goal cannot be achieved, nonstatin lipid-lowering agents, such as ezetimibe and bile-acid binding resins, can be added. An alternative option is the use of nonstatin lipid-lowering agents in place of statin therapy. The use of fibrates and niacin as monotherapy has been associated with myopathy. Therefore, bile acid resins may be the optimal choice in those patients without triglyceride abnormalities who cannot tolerate statin therapy.^[32]

Alternatives with a lower potential to induce myopathy have been explored, including the use of fluvastatin extended release, low-dose rosuvastatin, every-other-day dosing of atorvastatin or rosuvastatin, and twice weekly rosuvastatin, though these regimens are not approved by the FDA.^[7]

There has also been interest in the use of CoQ₁₀, Chinese red rice yeast, and vitamin D as prevention and/or management of statin-associated myopathy. Studies have not shown a correlation between intramuscular CoQ₁₀ levels and statin-induced myopathy. Additionally, randomized, controlled trials evaluating the use of CoQ₁₀ as prevention have yielded equivocal results.^[3] The NLA does not endorse the use of CoQ₁₀ as treatment.^[12,13] Chinese red rice yeast has been used for its LDL-lowering effects. This agent contains lovastatin and has been tolerated in those patients with an aversion to standard statin treatment. Clinical studies have not yielded significant results.^[33]

Additionally, the role of vitamin D has been somewhat controversial, as low levels are associated with both myalgia and poor muscle function. Studies evaluating vitamin D supplementation as prevention have been limited in their design and require validation through a larger randomized, double-blind, placebo-controlled trial.^[34]

Educating the patient on the warning signs and risks of myopathy can prevent serious complications. While many patients may self-treat their symptoms with analgesics or pain relievers, any sudden unexplained muscle weakness or other symptoms should be conveyed to their physician.

US Pharmacist © 2012 Jobson Publishing