Acute dystonia with low-dosage aripiprazole in Tourette's disorder.

Objective: To report a case of an acute dystonic episode in a patient with Tourette's disorder (TD) treated with the partial dopamine agonist aripiprazole.

Case Summary: An 18-year-old male with TD was prescribed aripiprazole 10 mg orally daily, which produced a significant improvement in his symptoms. However, after 3 days of treatment, he experienced an acute episode of dystonia with facial muscle spasm, oculogyric crisis, and torticolis. All symptoms resolved after a single intramuscular injection of biperidine 5 mg. The Naranjo probability scale indicated that the adverse events were probably caused by aripiprazole.

Discussion: To our knowledge, as of this writing, this is the first report concerning an aripiprazole-induced dystonic episode in an adult, and it is especially notable because it occurred at low dosage. Aripiprazole is a dopamine partial agonist and a serotonin(2A) antagonist with a favorable adverse effect profile. Short-term clinical trials reported a very low incidence of extrapyramidal symptoms, with akathisia being the most common, although there have been reports of severe extrapyramidal symptoms in a 3-year-old child and in an adolescent with a previous history of such symptoms.

Conclusions: Acute dystonic phenomena may be caused by aripiprazole, although the drug's suggested mode of action largely precludes them.