Randomized double-blind multicentre placebo-controlled clinical trial of the clonidine adhesive patch for the treatment of tic disorders.

OBJECTIVE: The aim of the present study was to evaluate the therapeutic effectiveness and safety of the clonidine adhesive patch in treating tic disorders. METHOD: 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 or =4 by the end of week 3 were withdrawn from the trial. RESULTS: 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. CONCLUSIONS: The clonidine adhesive patch is effective and safe for tic disorders.