She's on (= is taking) tranquillizers.
她在服用镇静剂。
牛津词典
Sex is safest tranquillizer in the world.
性爱是世界上最安全的镇定剂.
期刊摘选
The patient is verry worried, so the doctor gives him a shot of tranquillizer.
由于病人烦躁不安, 医生为他打了一针镇静剂.
期刊摘选
Use as in pharmacy industry synthetic tranquillizer and anaesthetic.
在制药工业中用作合成镇静剂和麻醉剂.
期刊摘选