Statins

Symptoms of Statin-Induced Myopathy

• Typically affects large proximal muscles (thighs, buttocks)

• Often presents 4–6 weeks after initiating therapy or increasing dose

• Aching or stiffness rather than sharp or cramping pain

• Pain is bilateral and generalised

Risk Factors for Myopathy

• Higher-potency statins or high-dose regimens (e.g. rosuvastatin ≥20 mg, simvastatin ≥40 mg)

• Concomitant use of certain medications (e.g. fibrates, macrolide antibiotics, strong CYP3A4 inhibitors)

• Older age, low body mass, female sex

• Vitamin D deficiency or hypothyroidism

• Excessive alcohol intake and poorly controlled diabetes

Bloods and Myopathy

• Elevated CK is common with high-potency statins

• CK levels typically reduce after cessation of the offending agent

• Check thyroid function (TSH) and vitamin D levels in unexplained myopathy

Management of Statin Myopathy

• Stop Statin

  • CK <5× ULN: Stop for 2–4 weeks

  • CK >5× ULN: Stop for 6–8 weeks; recheck CK before restarting

• Reintroduce Therapy

  • If symptoms improve, restart at a reduced dose or switch to a different statin

  • If symptoms recur, trial low-dose, high-potency statin (e.g. rosuvastatin) with intermittent dosing (e.g. alternate-day dosing)

  • Consider ezetimibe if intolerant to all statins

• Persistent Symptoms

  • Investigate for other causes of myopathy (e.g. hypothyroidism, vitamin D deficiency, polymyalgia rheumatica)

  • Shared decision-making is crucial to weigh cardiovascular benefits against potential adverse effects

Managing Elevated LFTs

• Mild asymptomatic transaminase elevation is not always an indication to cease therapy

• Accept ALT up to 3× ULN (confirm on at least two occasions)

• If ALT >3× ULN, lower the statin dose or consider switching to an alternative agent

• Pre-statin LFTs are recommended, with repeat tests only if clinically indicated

Best Statins for CKD/CLD

• CKD: Atorvastatin and pravastatin are preferred due to safer renal profiles

• Chronic Liver Disease: Pravastatin is least dependent on hepatic metabolism and is often favoured if mild-to-moderate liver impairment is present

Notes:

• Statin Intolerance

  • Use a structured approach to confirm true intolerance, as many patients can tolerate a different dose or formulation

  • Consider adjunctive therapies (e.g. ezetimibe, PCSK9 inhibitors) for high-risk patients who cannot achieve target LDL levels with statins alone

• Monitoring

  • Routine CK monitoring is not universally recommended unless the patient develops suggestive symptoms

  • LFTs can be repeated if clinical suspicion arises for hepatotoxicity

• Lifestyle Measures

  • Reinforce diet modifications, regular exercise, and weight management to optimise lipid control and reduce CVD risk

  • Address modifiable risk factors (e.g. smoking cessation, diabetes control, hypertension management) for comprehensive cardiovascular protection