Compounds of formula (I) below are disclosed. Their use as medicaments is described, in particular for the treatment of pain or inflammation: wherein: when X=Y=Z=OH, R1 is OCH2CF2CF3, phenoxy (substituted with 3-(4-trifluoromethylphenyl), 3,4-dichloro, (3-trifluoromethyl,4-fluoro), (3-trifluoromethyl,4-chloro), (3-chloro, 4-cyano), or 3,5-bis(trifluoromethyl)), 1-piperazinyl(4-(3,4-dichlorophenyl)), phenyl (substituted with 3,4-dichloro, 3,5-difluoro, 3,5-bis(trifluoromethyl) or 3,4,5-trifluoro) or 2-benzofuranyl; or when X=Y=OH and Z=OMe, R1 is OCH3, OCH2CHF2, OCH2cyclopentyl, O-(2,5-difluorophenyl) or (S)-sec-butylamino; or when X=H and Y=Z=OH, R1 is n-hexylamino or cyclopentylamino; or when (IV) X=Z=OH and Y=H, R1 is cyclopentylamino; or a pharmaceutically acceptable salt thereof.