Drugs that affect skeletal muscle function fall into several categories. Some, such as neuromuscular blocking agents, are used during surgery to produce paralysis. Others, such as skeletal muscle relaxants, reduce muscle rigidity and spasms associated with various neurologic and musculoskeletal conditions. In addition, there are several drugs that influence metabolic and other processes in skeletal muscle, including the nutrients that are required for normal muscle function and that are used to prevent or lessen degenerative muscular conditions. For example, selenium and vitamin E are used to prevent or treat muscular dystrophies such as white muscle disease in foals. The steroidal, nonsteroidal, and various other anti-inflammatory drugs are also commonly used to treat short- and longterm inflammatory conditions involving skeletal muscle. Anabolic steroids promote muscle growth and development and are administered in selected cases in which serious muscle deterioration has developed as a complication of another disease.