Compounds of formula I or pharmaceutically acceptable salts thereof: wherein R1, R2, R3, R4, m and n are as defined in the specification as well as salts and pharmaceutical compositions including the compounds are prepared. They are useful in therapy, in particular in the management of pain.
化学式为I的化合物或其药学上可接受的盐:其中R1、R2、R3、R4、m和n如规范中所定义,以及制备该化合物的盐和药物组成物。它们在治疗中有用,特别是在疼痛管理方面。