Do corticosteroids (steroids) cause muscle weakness?

From the Guidelines

Steroids do not inherently weaken muscles, and in certain contexts, such as Duchenne muscular dystrophy, they can actually slow the decline in muscle strength and function. The use of glucocorticoids, like prednisone, has been shown to improve muscle strength in patients with Duchenne muscular dystrophy, with a favourable profile 1. However, it's crucial to differentiate between anabolic steroids, which promote muscle growth, and corticosteroids, which can lead to muscle weakness with long-term use, particularly at high doses.

When considering the impact of corticosteroids on muscle strength, it's essential to weigh the benefits against the potential harms. In the context of rheumatic disease, corticosteroids can have a profound impact on body composition, leading to central deposition of adipose tissue and a catabolic effect on bone and muscle 1. However, the relationship between corticosteroid dose and muscle weakness is complex, and the risk of adverse effects, including muscle atrophy and weakness, increases with higher doses and longer duration of treatment.

Key points to consider:

• Glucocorticoids can slow the decline in muscle strength and function in certain conditions, such as Duchenne muscular dystrophy 1.
• Corticosteroids can lead to muscle weakness with long-term use, particularly at high doses 1.
• The risk of muscle atrophy and weakness increases with higher doses and longer duration of treatment.
• It's essential to follow a doctor's instructions carefully regarding dosage and duration to minimize potential side effects.

In clinical practice, the decision to use corticosteroids should be based on a careful consideration of the potential benefits and harms, taking into account the individual patient's needs and circumstances. The most recent and highest quality evidence suggests that, in certain contexts, steroids can be beneficial for muscle strength, but it's crucial to use them judiciously and monitor for potential side effects 1.

From the FDA Drug Label

An acute myopathy has been observed with the use of high doses of corticosteroids, most often occurring in patients with disorders of neuromuscular transmission (e.g., myasthenia gravis), or in patients receiving concomitant therapy with neuromuscular blocking drugs (e.g., pancuronium). This acute myopathy is generalized, may involve ocular and respiratory muscles, and may result in quadriparesis. Concomitant use of anticholinesterase agents (e.g., neostigmine, pyridostigmine) and corticosteroids may produce severe weakness in patients with myasthenia gravis.

Steroids can weaken muscle, particularly with high doses or in patients with certain conditions such as myasthenia gravis.

• Acute myopathy may occur, involving ocular and respiratory muscles, and resulting in quadriparesis.
• Severe weakness may be produced in patients with myasthenia gravis when anticholinesterase agents and corticosteroids are used concomitantly 2, 2, 2.

From the Research

Effects of Steroids on Muscles

• Steroids can have both positive and negative effects on muscles, depending on the type and dosage of the steroid, as well as the individual's overall health and medical condition 3, 4.
• High-dose steroid therapy can lead to muscle atrophy and weakness, a condition known as steroid myopathy, which can interfere with daily activities 4.
• On the other hand, certain anabolic steroids, such as oxandrolone, have been shown to have anabolic effects and can be used to promote muscle growth and strength in patients with wasting and catabolic disorders 5, 6.

Mechanism of Steroid-Induced Muscle Weakness

• The mechanism of steroid-induced muscle weakness is not fully understood, but it is thought to involve an imbalance between anabolism and catabolism of muscle proteins, resulting in muscle atrophy 4.
• Steroid-mediated induction of ubiquitin ligases and suppression of mammalian/mechanistic target of rapamycin have been shown to contribute to muscle atrophy and weakness 4.

Clinical Implications

• Clinicians should be aware of the potential side effects of steroids, including muscle weakness and atrophy, and monitor patients closely for these adverse effects 3, 4.
• The use of corticosteroids for joint pain and other musculoskeletal conditions has been shown to provide moderate short-term benefits, but long-term effectiveness is limited and there are potential adverse effects, including toxicity to articular cartilage and systemic side effects 7.