Taking geodon (ziprasidone) and i have a muscle in the neck on the right side back and is tense. do i need congentin or change med. previously on seroquel, celexa?

Needs an examination: First things always first. If you're having muscle tension, stiffness, or pain in a specific muscle of the neck then, your doctor needs to know in order to determine its cause. After that a better decision can be made on medications to take, change, add, or subtract from your list. You list things such as jaw pain & an orthodontic retainer which could be contributing to muscle pain as well.

Muscle stiffness: Muscle stiffness is not a sign of EPS or Tardive Dyskinesia hence use anticholinergic is not indicated. A muscle relaxant will seem more appropriate. If still concerned have a Doctor do an asssessment for EPS