A drug used to produce muscle relaxation (excepting neuromuscular blocking agents). Its primary clinical and therapeutic use is the treatment of muscle spasm and immobility associated with strains, sprains, and injuries of the back and, to a lesser degree, injuries to the neck. Also used for the treatment of a variety of clinical conditions that have in common only the presence of skeletal muscle hyperactivity, for example, the muscle spasms that can occur in multiple sclerosis.