Schizophrenia and related disorders affect a sizable proportion of any population. Neuroleptic (antipsychotic) medications are the primary treatment for these disorders. Neuroleptic medications are associated with a variety of side effects including tardive dyskinesia. Dyskinesia is a disfiguring movement disorder of the orofacial region that can be tardive (having a slow or belated onset). Tardive dyskinesia is difficult to treat, despite experimentation with several treatments. Calcium channel blockers (diltiazem, nifedipine, nimodipine, verapamil) have been among these experimental treatments.