Tizanidine is a muscle relaxant medication used to treat muscle spasms and increased muscle tone caused by conditions such as multiple sclerosis, spinal cord injury, or other neurological disorders. It works by blocking nerve impulses that cause muscles to contract, thereby reducing muscle tone and spasms. Tizanidine is usually taken orally, and the dosage and duration of treatment may vary depending on the individual's condition and response to the medication. Side effects of tizanidine can include dizziness, drowsiness, dry mouth, and muscle weakness.