Promethazine 1 mg/kg elicited a drop in pain threshold, while 2 mg/kg increased it. However, both dosages of promethazine attenuated EAA obviously.

• 静注异丙嗪1mg/kg能降低痛阈,2mg/kg则提高痛阈,但2种剂量的异丙嗪均能减弱针刺镇痛。