Dantrolene sodium has been shown to decrease muscle tone, clonus and muscle spasm. The action of this agent is not selective for spastic muscles and it may cause generalized weakness, including weakness of the respiratory muscles. Tizanidine is used for the treatment of spasticity caused by multiple sclerosis and spinal cord injury. It differs from other antispasticity agents, enabling the avoidance of certain drug dependence, intolerance and interactions. Objective measures of muscle strength demonstrate no adverse effects from tizanidine.
Patients report less muscle weakness from tizanidine than baclofen or diazepam.
When combined with baclofen, tizanidine presents the opportunity to maximize side effects by reducing the dosage of both drugs. Range of motion exercises and other spasticity-reducing techniques can be used immediately following injection. This form of treatment generally lasts about 12 weeks, then another dose can be administered. Surgery can play a very important role in the treatment of chronic spasticity. Patients with acute injury to the central nervous system will have changes in their muscle tone which fluctuate during the recovery period, and surgery should not be undertaken during this time of change.