Statin-Associated Muscle Pain (Myalgia)

Clinical Definition and Spectrum

The American College of Cardiology states that statin-associated muscle pain (myalgia) is the most common adverse effect of statin therapy, occurring in 1-5% of patients in randomized trials but 5-10% in real-world clinical practice, and is characterized by subjective muscle pain or aches without significant creatine kinase elevation 1
Statin-associated muscle symptoms (SAMS) exist on a spectrum of severity, including myalgia, myositis/myopathy, rhabdomyolysis, and statin-associated autoimmune myopathy 1
Myalgia is the most common form of SAMS, characterized by muscle pain, aches, or soreness with normal or minimally elevated CK levels, occurring in approximately 5% of patients in both statin and placebo groups in controlled trials 2
Rhabdomyolysis is a rare but serious form of SAMS, characterized by CK >10 times upper limit of normal with evidence of renal injury, requiring immediate medical attention 1, 2

Myalgia is more likely statin-associated when it is bilateral and involves proximal muscles (shoulders, hips, thighs) 3
Myalgia is more likely statin-associated when it has onset within weeks to months after statin initiation 4
Myalgia is more likely statin-associated when it resolves after discontinuation of the statin 4
Myalgia is more likely statin-associated when it recurs with rechallenge 2

The American College of Cardiology identifies several patient characteristics that substantially increase myalgia risk, including age >80 years, small body frame and frailty, multisystem disease, polypharmacy, and drug interactions with CYP3A4 inhibitors 1, 4
Higher statin doses also increase the risk of myalgia 4
Asian ancestry is associated with an increased risk of myalgia 1
Hypothyroidism, vitamin D deficiency, and rheumatologic disorders are also associated with an increased risk of myalgia 4

The reported frequency of myalgia varies significantly by study design, with randomized controlled trials reporting a frequency of 1-5% and observational studies and clinical practice reporting a frequency of 5-10% 1, 2
Severe myopathy with significant CK elevation is rare, occurring in approximately 0.08-0.09% of patients 3
Fatal rhabdomyolysis is extremely rare, except with cerivastatin (withdrawn from market) which had 16-80 times higher risk than other statins 2

The American College of Cardiology recommends temporarily discontinuing the statin until symptoms can be evaluated, evaluating for alternative causes, checking CK levels, and rechallenging with a lower dose or different statin after symptom resolution 1, 4
If symptoms recur, trying a different statin or considering combination therapy with ezetimibe plus low-dose statin is recommended 4

The American College of Cardiology recommends immediately discontinuing statins and seeking urgent evaluation if severe muscle symptoms with weakness develop, CK >10 times upper limit of normal, dark urine, or acute conditions predisposing to renal failure occur 1, 2

The American College of Cardiology and American Heart Association recommend against the use of Coenzyme Q10 for routine use in patients treated with statins or for the treatment of statin-associated muscle symptoms, with a Class III: No Benefit recommendation, indicating the strongest level of evidence against its use 5

The 2019 ACC/AHA Cholesterol Management Guideline provides evidence that CoQ-10 supplementation does not reduce muscle symptoms in patients with confirmed statin myalgia, based on the highest quality evidence 5