Drug-induced and metabolic myopathy
The drugs that damage muscle (statins, steroids, colchicine, hydroxychloroquine, checkpoint inhibitors), the CK thresholds that change management, statin rechallenge and anti-HMGCR disease, and how exercise history separates glycogen, lipid and mitochondrial myopathies from endocrine causes.
Tier 2Condition
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Drugs are the commonest treatable cause of muscle symptoms in adults. Always take a drug history, including recent starts and new interactions.
- CK separates the high-CK causes (statins, colchicine, checkpoint inhibitors, hypothyroidism, alcohol) from normal-CK causes (steroids, hyperthyroidism, osteomalacia).
- Metabolic myopathies are inherited faults in muscle energy supply. They present with exercise intolerance, cramps and episodic rhabdomyolysis. Lipid disorders look normal between attacks; CK stays raised in most people with McArdle disease.
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Sources
- Therapeutic Guidelines: Cardiovascular (statin adverse effects and interactions)AU/NZTherapeutic Guidelines Limited (eTG complete), current online version, accessed November 2026
- Australian guideline for assessing and managing cardiovascular disease riskAU/NZAustralian Chronic Disease Prevention Alliance, 2023
- Kruijt N et al. 276th ENMC International Workshop: recommendations on optimal diagnostic pathway and management strategy for patients with acute rhabdomyolysis worldwide. Neuromuscul Disord 2025;50:105344European Neuromuscular Centre, 2025
- Allenbach Y et al. 224th ENMC international workshop: clinico-sero-pathological classification of immune-mediated necrotizing myopathies. Neuromuscul Disord 2018;28:87-99European Neuromuscular Centre, 2018
- Wood FA et al. N-of-1 trial of a statin, placebo, or no treatment to assess side effects (SAMSON). N Engl J Med 2020;383:2182-4New England Journal of Medicine, 2020
- Cholesterol Treatment Trialists' Collaboration. Effect of statin therapy on muscle symptoms: an individual participant data meta-analysis of large-scale, randomised, double-blind trials. Lancet 2022;400:832-45The Lancet, 2022
- Stroes ES et al. Statin-associated muscle symptoms: impact on statin therapy. European Atherosclerosis Society Consensus Panel Statement on Assessment, Aetiology and Management. Eur Heart J 2015;36:1012-22European Atherosclerosis Society, 2015
- Colgout (colchicine) Australian product informationAU/NZTherapeutic Goods Administration, 4 June 2026
- Last updated
- 14 November 2026
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