Methylprednisolone-Related Muscle Changes

Muscle-Related Side Effects of Methylprednisolone

• Loss of muscle mass and type 2 fiber atrophy occur with corticosteroid use, particularly when combined with neuromuscular blocking agents in critically ill patients 1, 2
• The American Thoracic Society and other guideline societies may recommend monitoring for muscle weakness and myopathy in patients on corticosteroids, as these are well-documented adverse effects, with a strength of evidence level of high 1, 2

Clinical Patterns of Steroid-Induced Muscle Changes

• Acute myopathy occurs after short-term treatment with high doses, causing generalized muscle atrophy and rhabdomyolysis, manifesting as diffuse flaccid weakness, with a moderate level of evidence 1, 2
• Chronic steroid myopathy develops after prolonged treatment, characterized by gradual proximal limb weakness without cramping as a primary feature, although the evidence for this is based on 1, 2

Clinical Monitoring Recommendations

• Consider CPK levels if myopathy is suspected, particularly in critically ill patients receiving concurrent neuromuscular blocking agents, with a recommendation grade of strong 1, 2