Clinical Presentation and Management of Acute Dystonia from Drug Abuse or Misuse in Adolescents and Young Adults: A Retrospective Cohort Study in Bangkok, Thailand.

Objectives: To describe the clinical presentation of acute dystonia (AD) from drug abuse or misuse, as well as the emergency department (ED) management and outcomes in adolescents and young adults. Methods: This was a retrospective cohort study of patients aged 10-25 years who were admitted to the ED for AD due to intentional abuse or misuse from January 1, 2014, to June 30, 2017. Data were collected from electronic medical records by three investigators with excellent interrater reliability (0.87). Results: Sixty-two cases met the criteria with male predominance (85.5%); the mean age was 16.7 years. Perphenazine was the most common cause of AD (38.7%), followed by haloperidol (32.2%). The most common AD manifestations were torticollis (51.6%), oromandibular dystonia (45.2%), and oculogyric crisis (22.6%). Intravenous (IV) diazepam combined with oral trihexyphenidyl and IV diazepam alone were the most frequently used first treatment in our ED (41.7% and 35.0%, respectively). Overall, the improvement rates from IV diazepam alone or combined with trihexyphenidyl ranged from 46.2%-75.0%. These rates were inferior to those observed with IV benztropine (100%) alone or combined with trihexyphenidyl. All patients were treated on an outpatient basis, except for one who was admitted to a pediatric ward. Conclusions: In recent years, drug-induced AD caused by intentional abuse among adolescents and young adults has become a concern in Thailand. The most common suspected drugs of abuse were first-generation antipsychotics, perphenazine, and haloperidol. The most effective treatment was benztropine.