[Xifeng zhidong tablet and the placebo control treatment of tic disorder children patients of internal disturbance of Gan-wind with phlegm syndrome: a clinical study]. OBJECTIVE: To assess the efficacy and safety of Xifeng Zhidong Tablet (XZT) in treating tic disorder children patients of internal disturbance of Gan-wind with phlegm syndrome (IDGWPS). METHODS: A stratified randomized, double-blinded, parallel control of placebo, multi-center trial was conducted in 160 subjects from 5 hospitals in China. They were randomly assigned to 2 groups, the test group and the control group, 80 in each group. Those in the test group were treated with XZT, while those in the control group were treated with placebos. The therapeutic course was 4 weeks for all. The effectiveness indicators covered main indicators and secondary indicators. Yale global tic severity scale (YGTSS) was taken as the main indicators. The amelioration of social function impairment, efficacy, single index of Chinese medical syndromes, Chinese medical syndrome efficacy as well as disappearance rate of single Chinese medical symptoms were evaluated as secondary indicators. The safety indicators included clinical adverse events, vital signs, blood/urine/stool routines, renal and liver functions, and electrocardiogram (ECG). RESULTS: As for main indicators, the score of YGTSS decreased from 22.10 +/- 6.38 to 11.34 +/- 6.58 in the test group, while it decreased from 22.65 +/- 6.70 to 16.82 +/- 6.53 in the control group, showing statistical difference when compared with the same group before treatment (P < 0.01). Besides, the decrement was more significant in the test group after treatment (P < 0.05). As for secondary indicators, the total effective rate was 83.54% in the test group and 34.18% in the controlled group, showing statistical difference between the two groups (P < 0.05). As for social function impairment, 20,38, 16, 3, 1 case(s) in the test group were ranked as normal, minimal, mild, moderate, obvious degree, while 1, 24, 45, 7, and 0 case(s) in the control group were ranked as normal, minimal, mild, moderate, obvious degree. Better effect was obtained in the test group (P < 0.05).As for Chinese medical syndrome efficacy, it was 87.34% in the test group and 64.56% in the control group (P < 0.05). As for single index of Chinese medical syndromes, the disappearance rate of motor tics, irritability, dreaminess, abnormal tongue proper,abnormal tongue fur, and abnormal tongue pulse condition was 78.67%, 34.72%, 62.26%, 34.62%, 58.97%, and 39.74%, respectively in the test group, while they were 34.67%, 13.11%, 21.82%, 15.58%, 25.97%, and 19.48%, respectively in the control group. Better results were shown in the test group (P < 0.05). Totally 5 adverse events occurred. The incidence of adverse events was 3.75% in the test group and 2.53% in the control group. CONCLUSIONS: After 4 weeks of XZT treatment, the integral of YGTSS could be obviously reduced, the degree of social function impairment ameliorated, and Chinese medical syndromes improved. In addition, no adverse reaction occurred in this study.