Varenicline-induced acute dystonic reaction: a case report.

Dystonia is a syndrome characterized by sustained muscle contractions frequently causing twisting and repetitive movements or abnormal postures. Dystonic reactions may be a complication of many drugs such as antipsychotics, anti-emetics and antidepressants. This report presents a 25-year-old patient who was admitted to an emergency department with acute dystonia following the use of varenicline, a pharmacological agent used for the treatment of nicotine addiction. Dystonic reactions may be related to the dopaminergic deficiency caused by the use of varenicline. In conclusion, this report suggests that varenicline can cause dystonic reaction in at least some patients.