Tics and other stereotyped movements as side effects of pharmacological treatment

Tics and other stereotyped abnormal movements can be seen as adverse effects of some pharmacologic drugs. Among these drugs, antipsychotics may provoke tardive syndromes after a chronic exposure, primarily in the case of typical antipsychotics. These syndromes include tardive tics, tardive dyskinesia, or tardive akathisia, which present with tics or stereotyped movements as a clinical phenomenon. Psychostimulants (mainly methylphenidate) have traditionally been associated with the appearance of tics due to the increased dopamine activity caused by stimulants. Nevertheless, in recent years, several studies have concluded not only that methylphenidate does not exacerbate or reactivate tics but also that tics can improve with its use in patients with associated attention deficit and hyperactivity disorder and tic disorder. Antiepileptic drugs, although infrequently, can also induce tics, with carbamazepine and lamotrigine described as tic inducers. Other antiepileptics, including levetiracetam and topiramate, have been proposed as a potential treatment for tic disorders due to a positive effect on tics, especially in those with associated epileptic disorder. Clinical and therapeutic approaches to tics and stereotyped movements after exposure to antipsychotics, stimulants, and antiepileptic drugs will be reviewed in this chapter.