Randomized double-blind multicentre placebo-controlled clinical trial of the clonidine adhesive patch for the treatment of tic disorders.
The aim of the present study was to evaluate the therapeutic effectiveness and safety of the clonidine adhesive patch in treating tic disorders. A total of 437 patients, who met Chinese Classification of Mental Disorders-third edition diagnostic criteria for transient tic disorder (5%), chronic motor or vocal tic disorder (40%) or Tourette disorder (55%), aged 6-18 years, were divided randomly into an active treatment group and a clinical control group. Participants in the active treatment group were treated with a clonidine adhesive patch and participants in the clinical control group with a placebo adhesive patch for 4 weeks. The dosage of the clonidine adhesive patch was 1.0mg, 1.5mg or 2.0mg per week, depending on each participant's bodyweight. Participants whose Yale Global Tic Severity Scale (YGTSS) score decreased <30% and Clinical Global Impression score was > or =4 by the end of week 3 were withdrawn from the trial. After 4 weeks of treatment the active treatment group participants' YGTSS score was significantly lower than that of the clinical control group (F=4.63, p=0.03). Further, the active treatment group had a significantly better therapeutic response than the clinical control group (chi(2)=9.15, p=0.003). The response rate in the active treatment group was 68.85% compared to 46.85% in the clinical control group (chi(2)=16.98, p=0.0001). The rate of adverse events was low (active treatment group, 3.08%; clinical control group, 7.21%) and did not differ between the two groups. The clonidine adhesive patch is effective and safe for tic disorders.