Drugs Affecting Skeletal Muscle

Pharmacologic management of equine skeletal muscle disorders is essential for reducing pain, restoring function, and preventing complications that affect performance and welfare. These disorders are classified as exertional or non-exertional and subclassified based on rhabdomyolysis and membrane conduction abnormalities. Treatment strategies to address pain, inflammation, and muscle contracture include analgesics, non-steroidal anti-inflammatory drugs, corticosteroids, tranquilizers, centrally acting muscle relaxants, neuromuscular blockers, and antioxidants. The roles of acepromazine, methocarbamol, dantrolene, and anabolic steroids in muscle relaxation, pain control, and performance optimization are discussed. Nutritional and toxic myopathies, immune-mediated myositis, and genetic disorders – including polysaccharide storage myopathy and hyperkalemic periodic paralysis – require individualized therapy tailored to pathophysiology and severity. Intramuscular drug administration is common but may cause adverse effects such as myalgia, inflammation, and myonecrosis, underscoring the need for careful technique and monitoring. Emphasis is placed on evidence-based protocols and emerging research aimed at improving outcomes and minimizing complications.