Atomoxetine and tics in ADHD.

Atomoxetine is a nonstimulant medication shown to be efficacious in the treatment of attention-deficit/hyperactivity disorder (ADHD). There have been no reports to date of tics being precipitated or exacerbated by atomoxetine. We report four patients with ADHD who had developed tics on stimulants and in whom tics reappeared or were exacerbated on atomoxetine. Moreover, the tics resolved or abated significantly when atomoxetine was discontinued. The possibility of tics as an adverse effect of atomoxetine may also shed light on the neurochemical systems involved in patients with comorbid ADHD and tic disorders. The first patient is a 9-year-old adopted boy with unknown family history and no history of tics. He was first diagnosed with ADHD, combined type, in March 2002 and treated with methylphenidate and then with Adderall (amphetamine/dextroamphetamine) and dextroamphetamine. Upon starting medications, he developed motor tics that ceased upon discontinuation of treatment. He remained medication free for 6 months. Because of the persistence of ADHD symptoms, he was started on atomoxetine at 10 mg every morning in June 2002, and the dose was increased to 20 mg every morning after 1 week. Within a few days of the dose increase, he developed motor tics consisting of rapid, severe eye blinking, similar to those he developed previously on stimulants. There were no vocal tics. The medication was stopped, and the tics ceased within 1 to 2 days. He was then started on guanfacine, on which his ADHD is well controlled, and there has not been a recurrence of tics for more than a year. The second patient is a 14-year-old white boy diagnosed with ADHD, predominantly inattentive type. He developed an eye-blinking motor tic on Concerta (methylphenidate), which was discontinued. He was then started on atomoxetine 20 mg q.d.; however, the eye blinking worsened, and he started developing a vocal tic of severe bouts of throat clearing. After a few days, atomoxetine was discontinued, the vocal tics resolved, and eye blinking diminished. He is currently on guanfacine with only mild eye blinking persisting. The third and fourth patients are both boys, 9 and 15 years old, with histories of chronic tic disorder and ADHD. They had also experienced tic exacerbations on stimulants. For the 9-year-old, within a month of starting atomoxetine up to 18 mg q.d., he developed dramatic vocal tics and increased motor tics accompanied by irritability, anxiety, dysphoria, compulsive finger picking, and obsessional ruminations, whereas he only had …