Tizanidine is a medication used to treat muscle spasms and spasticity, which are caused by various conditions such as multiple sclerosis, spinal cord injury, or certain neurological disorders. Tizanidine works by blocking nerve impulses that are sent to the brain, which reduces muscle tone and relieves spasms. It is typically taken orally in tablet form, and the dosage and duration of treatment depend on the individual's condition and response to the medication. As with any medication, tizanidine can have side effects and should only be used under the supervision of a healthcare provider.