A compound of formula (I) wherein X is O S SO or SO R is halogen trihalomethyl OH Calkyl Calkoxy trifluoromethoxy phenoxy cyclohexylmethyloxy pyridylmethoxy cinnamyloxy naphthylmethoxy phenoxymethyl CH OH CH CH OH Calkylthio Calkylsulfinyl Calkylsulfonyl benzylthio acetyl nitro or cyano or phenyl phenylCalkyl or phenyl Calkoxy each phenyl group thereof being optionally substituted by halogen CF Calkyl or Calkoxy R is H halogen trihalomethyl Calkoxy Calkyl phenethyl or benzyloxy R H halogen CF OH Calkyl Calkoxy benzyloxy phenyl or Calkoxymethyl each of R and R independently is H or a residue of formula (a) wherein each of R and R independently is H or Calkyl optionally substituted by halogen and n is an integer from 1 to 4 or a pharmaceutically acceptable salt hydrate solvate isomer or prodrug thereof or a compound of formula (II) wherein R is halogen trihalomethyl Calkyl Calkoxy Calkylthio Calkylsulifinyl Calkyl sulfonyl aralkyl optionally substituted phenoxy or aralkyloxy R is H halogen trihalomethyl Calkyl Calkoxy aralkyl or aralkyloxy R is H halogen CF Calkyl Calkoxy Calkylthio or benzyloxy R is H Calkyl phenyl optionally substituted benzyl or benzoyl or lower aliphatic Cacyl R is H monohalomethyl Calkyl Calkoxy methyl Calkyl thiomethyl hydroxyethyl hydroxypropyl phenyl aralkyl Calkenyl or alkynyl R is H or Calkyl R is H C1alkyl or a residue of formula (a) as defined above X is O S SO or SO and n is an integer of 1 to 4 or a pharmaceutically acceptable salt hydrate solvate isomer or prodrug thereof for use in a method of treatment optionally of an autoimmune condition wherein said compound of formula (I) or (II) is administered at a dosage lower than the standard daily dosage of said compound during the initial period of treatment and then is increased optionally stepwise up to the standard daily dosage of said compound.
