Zanaflex is a relatively new medication. The major side effect is lethargy or feeling tired. Dantrium is a medication that works on the muscle directly rather than in the spinal cord. It is effective in some cases, but there is the potential for liver damage, particularly as individuals get a little older. It can also cause muscle weakness.
Some doctors also use medications that are injected into the muscle, such as phenol or botox.
Generally, these injections are better for small muscles and for spasticity that is not generalized to many places in the body. A decision needs to be made by the person with spasticity and their doctor regarding the need to treat spasticity. This is Dr. Flanagan's opinion and your own physician should be consulted prior using any medications. Sometimes, spasticity is actually helpful to a person. For instance, if a person has a weak leg, their spasticity may actually be helpful for standing and walking.