METHODS: 17 cancer patients were randomly given 30 mg controlled release morphine sulphate (CRMS) every 12 h or 10 mg immediate release morphine sulphate (IRMS) every 4 h for 7 days.

• 方法：17例癌症病人，随机poCRMS或IRMS7d，用GC?MS测定服药第5，6，7天吗啡血药浓度的峰谷水平。