Review Of: Murphy TK et al, J Child Adolesc Psychopharmacol 2017;20(20):1–9

Tic disorders, including Tourette’s, often co-occur with ADHD, OCD, and anxiety disorders. Guanfacine is often tried for all of these conditions. Randomized placebo-controlled trials of immediate release guanfacine have been mixed, with one showing 31% improvement in tics but another showing no significant improvement. Extended release (ER) guanfacine, while indicated for ADHD, has not been studied in children with tic disorders. Murphy et al set out to investigate its safety and efficacy as a treatment for chronic tic disorder (CTD).

This 8-week, double-blind, placebo-controlled trial included 34 subjects aged 6–17 years (mean 11 years), who met criteria for CTD. Children were either medication-free or on a stable OCD or anxiety regimen for at least 8 weeks. Participants were randomly assigned to either guanfacine ER (n = 16) or placebo (n = 18). Those in the medication group received a starting dose of 1 mg in the morning, which could be increased to as much as 4 mg per day and divided into two doses at the clinician’s discretion. Mean guanfacine ER dose was 2.6 mg. The primary outcome was change from baseline in the Yale Global Tic Severity Scale (YGTSS).

At 8 weeks, both groups had a few positive responders on the YGTSS; however, there was no significant difference between guanfacine ER (19%; 3/16) and placebo (22%; 4/18). Parent ratings of tic severity in the guanfacine group showed improvement, whereas no effect was seen with placebo. In addition, only the guanfacine group showed an improvement in ADHD symptoms. Common side effects in patients on guanfacine included fatigue, drowsiness, dry mouth, headache, irritability, stomachache, and decreased appetite.

CCPR’s Take
In this small pilot study, guanfacine ER was no more effective than placebo for improving symptoms in children with CTD. On the other hand, it did not worsen tics, which is reassuring, especially since stimulants can aggravate tics when used for ADHD. Guanfacine may have a place in treating ADHD specifically for children with tic disorder, with the modest goal of easing ADHD symptoms while at least not worsening tics.