What is the appropriate management for a 73‑year‑old patient on rosuvastatin who presents with severe lower‑limb pain?

Management of Severe Lower Limb Pain in a 73-Year-Old on Rosuvastatin

Immediately discontinue rosuvastatin and obtain creatine kinase (CK), thyroid-stimulating hormone (TSH), vitamin D, serum creatinine, ALT, and AST levels to evaluate for statin-induced myopathy and identify contributing factors. 1, 2

Immediate Actions

Stop rosuvastatin now – do not wait for laboratory results if the patient has severe bilateral lower limb pain, as this presentation is highly consistent with statin-induced myopathy and delay risks progression to rhabdomyolysis. 1, 2, 3

Essential Laboratory Work-Up

• Measure CK immediately and compare to any baseline value obtained before starting rosuvastatin; this is the single most important test to guide management. 1, 2
• Check TSH in every patient with statin-related muscle pain, as hypothyroidism predisposes to myopathy and can exacerbate statin-induced muscle injury. 1, 2, 4
• Obtain vitamin D (25-OH) level, since deficiency is a common reversible contributor to muscle discomfort on statins. 1, 2, 4
• Assess renal function (serum creatinine) and urinalysis for myoglobinuria, particularly important given the patient's age and risk of acute kidney injury from rhabdomyolysis. 1, 2
• Measure ALT and AST to evaluate for concurrent hepatotoxicity. 1, 2

Interpretation of CK Results and Management Algorithm

If CK > 10 × Upper Limit of Normal (ULN)

• Keep rosuvastatin discontinued permanently – this threshold indicates significant myopathy with high risk of rhabdomyolysis. 1, 2
• Monitor CK every 2 weeks until normalization and assess renal function closely. 2
• Do not rechallenge with any statin until at least 2 months after complete symptom resolution and CK normalization. 4

If CK 3-10 × ULN with Severe Symptoms

• Discontinue rosuvastatin and monitor CK weekly until symptoms resolve and CK normalizes. 1, 2
• Wait for complete symptom resolution (typically 2-6 weeks) before considering any rechallenge. 2, 4

If CK < 3 × ULN but Severe Symptoms Present

• Still discontinue rosuvastatin – normal or minimally elevated CK does not exclude statin-induced myopathy, as 5-10% of patients develop myopathy with minimal or no CK elevation. 4, 5
• Do not dismiss the patient's symptoms based on normal CK alone; muscle pain without CK elevation is the most common manifestation of statin myopathy. 1, 5

Critical Risk Factors in This 73-Year-Old Patient

This patient has multiple high-risk features that substantially increase myopathy risk:

• Advanced age (73 years) – older patients have dramatically higher myopathy risk. 4, 5, 6
• Rosuvastatin specifically – while all statins carry myopathy risk, rosuvastatin at higher doses has documented severe myopathy cases including bilateral lower limb weakness and acute kidney injury. 3, 7, 6
• Potential undiagnosed hypothyroidism or vitamin D deficiency – must be ruled out as these are reversible contributors. 1, 2, 4
• Possible renal impairment – common in elderly patients and dramatically increases myopathy risk. 1, 2, 6

Timeline for Symptom Resolution

• Expect symptom resolution within 2-8 weeks after stopping rosuvastatin in most cases. 4, 8
• If symptoms persist beyond 2 months, the pain is likely NOT caused by rosuvastatin and alternative diagnoses (polymyalgia rheumatica, primary muscle disease, rheumatologic conditions) must be pursued. 2, 4

Rechallenge Strategy After Complete Resolution

Do not attempt rechallenge until symptoms have completely resolved and CK has normalized (if it was elevated). 1, 2, 4

Step 1: Consider Alternative Statin with Lower Myopathy Risk

• Pravastatin or fluvastatin are preferred alternatives due to lower myopathy risk compared to rosuvastatin. 1, 4, 8, 5
• Start with the lowest available dose and monitor closely for symptom recurrence. 1, 4

Step 2: Alternative Dosing Regimens

• Alternate-day dosing with long-half-life statins (atorvastatin 10-20 mg or rosuvastatin 5-10 mg every other day) may be better tolerated. 4, 8, 5
• Twice-weekly dosing of rosuvastatin 5-10 mg is another option if daily therapy cannot be tolerated. 4, 5

Step 3: Combination Therapy to Minimize Statin Dose

• Combine the lowest tolerated statin dose with ezetimibe 10 mg daily to achieve lipid goals while minimizing statin exposure. 8, 5
• Consider bempedoic acid as an alternative lipid-lowering agent that is activated only in the liver (not muscle) and carries no myopathy risk. 1

Common Pitfalls to Avoid

• Do not continue rosuvastatin while "monitoring" the patient – severe bilateral lower limb pain mandates immediate discontinuation. 1, 2
• Do not attribute symptoms to "old age" or "arthritis" without proper evaluation – statin myopathy is common (5-10% of patients) and reversible if caught early. 5, 7
• Do not rechallenge with the same dose of rosuvastatin – if rechallenge is attempted, use a different statin at a much lower dose. 1, 4
• Do not ignore normal CK in the presence of severe symptoms – most statin myopathy presents with pain but minimal CK elevation. 1, 4, 5

Special Consideration: Statin-Associated Autoimmune Myopathy

• If muscle weakness and CK elevation persist despite rosuvastatin discontinuation beyond 2 months, consider rare statin-associated autoimmune necrotizing myopathy (anti-HMGCR antibody positive), which requires immunosuppressive therapy and neurology referral. 1, 2

Cardiovascular Risk Management During Statin Holiday

• Initiate ezetimibe 10 mg daily immediately to maintain some lipid-lowering effect while rosuvastatin is held. 8, 5
• Optimize other cardiovascular risk factors (blood pressure control, antiplatelet therapy, diabetes management) during the statin-free period. 9